The objectives of this study were to evaluate growth, yield and nutrients removal of five cassava cultivars planted by different planting methods in late rainy season of northeastern Thailand. A split plot design was used in this study. The planting methods (vertical and horizontal) were assigned as main-plots. Cassava cultivars (Rayong-7, Rayong-11, Rayong-72, Huaybong-80 and E-dum) were assigned as sub-plots with four replications. Results showed that vertical planting gave significantly higher fresh storage root yield than those of horizontal planting, across five cassava cultivars. The cultivar Rayong-7 produced maximum fresh storage root yield across two planting methods, but not significantly different from Rayong 11, Huaybong 80 and Edum cultivars. Irrespective of nutrient removal, N, P and K removed ranges from 2.9 - 3.6, 0.8 - 1.3 and 5.3 - 7.9 kg per ton fresh root weight, respectively depending on cassava cultivar. The cultivar Rayong-7 removed the highest quantities of N, and the cultivar Rayong-11 removed maximum of P and K in the present study. Regardless of nutrient removal at different plant parts; N, P and K removed maximum quantities in leaf, stem and storage root, respectively. Planting method had no significant effect on N and P removal, but significant effect on K removal. The vertical planting removed K higher than those of horizontal planting.
Cassava (Manihot esculenta Crantz) has been recognized as one of the most important subsidiary cash crops in northeastern Thailand. The average total area planted to the crop and production of cassava per annum in northeastern Thailand is 0.74 million hectares and 15.9 million tones, respectively [
A field experiment was carried out at the Faculty of Agriculture Farm, Khon Kaen University (latitude 16˚28'N, longitude 120˚48'E, 200 m a.s.l) in 2014-2015. The planting date was December 18th, and the crops were harvested 300 days after planting (DAP). The soil texture of the experimental area is loamy sand with 6.6 pH, 0.19% total N, 38.11 mg∙kg−1 available P, and 40.2 mg∙kg−1 exchangeable K. The field capacity (FC) and permanent wilting point (PWP) of the soil were 13.2% and 2.8%, respectively.
The split plot design with four replications was used in this study. Two planting methods; vertical planting (stem cutting inserted into the soil forming 90˚ angles on top of ridges) and horizontal planting (stem cutting forming 180˚ angles with soil surface placed in furrow was assigned as main-plot) and five cassava cultivars (Rayong-7, Rayong-11, Rayong-72, Huaybong-80 and E-dum) were assigned as sub-plots. A four-wheel tractor was used to prepare the land by plowing twice, and creating ridges. The distance between rows and plant of cassava was about 1 × 1 m, and the ridge height was about 0.4 m. The mature stems were cut about 15 cm long and vertical planting inserted into moist soil with two- thirds of the length on top of the ridges. In case of horizontal planting, the stem cutting was horizontally placed in furrows made by hand hoes on top of the ridges to the depth of 10 cm and fully covered by soil. Chemical fertilizer formula 15-15-15 (N, P2O5, K2O) at rate of 312 kg∙ha−1 was applied one month after planting. Hand weeding was done once before fertilizer application. Pesticides were not used throughout the growing period. Water was applied once with sprinkler irrigation at 7 DAP to provide good crop germination. Thereafter, the crop received only rainfall until harvest (
Data on adventitious root dry weight was measured at 45 DAP. Above ground dry weight was recorded at 45, 110, 210 and 300 DAP. The number of storage roots per plant, weight of storage roots per plant and fresh storage root yield were determined at 300 DAP in the harvesting area of each plot. The contents of starch in storages root were measured by specific gravity method. The harvest index was calculated from storage roots dry matter divided by total dry matter. Leaf samples were taken during the drought phase at 60, 80 and 110 DAP outside the harvesting area to determine relative water content (RWC). Three leaves of the fourth fully-expanded from the top of each plant within plot were sampled, and twenty leaf disks (1.5 × 2.0 cm, wide × long) were excised from the
Month | Temperature (˚C) | Rainfall | ET | RH | Sunshine | |
---|---|---|---|---|---|---|
Maximum | Minimum | (mm) | (mm∙day−1) | (%) | (h∙day−1) | |
Year 2013 | ||||||
December | 27.5 | 14.5 | 26.2 | 4.63 | 86 | 8.27 |
Year 2014 | ||||||
January | 29.7 | 13.7 | 0 | 4.91 | 84 | 9.04 |
February | 33.4 | 19.2 | 0 | 5.37 | 81 | 7.78 |
March | 36.6 | 23.4 | 2.7 | 6.25 | 82 | 8.02 |
April | 35.6 | 24.6 | 164.2 | 5.49 | 87 | 7.55 |
May | 35.9 | 24.9 | 75.7 | 5.49 | 87 | 8.04 |
June | 35.3 | 25.8 | 102.1 | 5.61 | 86 | 6.46 |
July | 32.7 | 24.7 | 188.9 | 4.46 | 90 | 3.20 |
August | 32.9 | 24.3 | 209.2 | 4.33 | 91 | 4.33 |
September | 32.5 | 23.9 | 155.9 | 4.09 | 90 | 4.86 |
October | 29.8 | 22.9 | 50.7 | 4.21 | 84 | 7.69 |
ET = pan evaporation, RH = relative humidity.
middle of center lobe (avoiding the midrib) weighed and placed in a petri dish of distilled water for 4 hours, re-weighed to determine hydration weight (HW), and then dried at 60˚C for 48 hours for dry weight (DW) determination, RWC was then calculated by dividing the difference between fresh weight and dry weight by the difference between HW and DW [
Dry matter harvests and samples for plant nutrient analysis such as leaf, stem and storage root were collected at 300 DAP. Samples of stems were collected from the middle one-third of three plants, and root samples were obtained from four randomly selected medium sized storage roots. Leaves were collected from the entire plant. Samples were dried at 60˚C, ground and analyzed for total N, total P and total K concentration. Nitrogen concentration was measured by micro kjeldahl method, P concentration by emission spectrophotometer and K concentration by emission flame photometer. Nitrogen, phosphorus and potassium uptake were calculated by multiplying the quantity of dry matter for plants part with nutrient concentration. Regardless of nutrient returning, the dropping leaves were collected three times during the cropping season with sampled areas of 2 × 6 meter from each plot outside harvesting area. The nutrient concentration and uptake were measured as the same procedures with nutrient removal.
The weather data was recorded in an open field at a distance of 350 m from the experimental field. The values of air temperature (maximum and minimum), relative humidity, incoming sun light, pan evaporation and rainfall are shown in
Planting methods did not have significant effect on above ground dry weight (AGDW) at 45, 110, 210 and 300 days after planting (DAP), as well as adventitious root dry weight (ARDW) at 45 DAP (
The cultivar HB-80 gave the highest AGDW at 110, 210 and 300 DAP. The ARDW had significant effect with respect to cassava cultivars (
Planting methods had significant effects on the number of storage roots per
Treatment | Above ground dry weight (gm∙plant−1) | ARDW (gm∙plant−1) | |||||
---|---|---|---|---|---|---|---|
45 | 110 | 210 | 300 | ||||
DAP | |||||||
Planting method (M) | |||||||
Vertical | 6.9 | 183.8 | 851.5 | 1059.1 | 0.67 | ||
Horizontal | 6.6 | 167.6 | 752.3 | 867.2 | 0.66 | ||
Cultivar (C) | |||||||
Rayong-7 | 7.2 | 178.2 a | 1052.5 a | 946.9 b | 0.88 a | ||
Rayong-11 | 6.6 | 223.4 a | 534.0 b | 937.1 b | 0.71 ab | ||
Rayong-72 | 5.3 | 116.0 b | 502.5 b | 592.0 c | 0.46 b | ||
Huaybong-80 | 7.4 | 185.7 a | 994.6 a | 1195.1 a | 0.47 b | ||
E-dum | 7.6. | 175.4 a | 952.8 a | 1144.0 ab | 0.80 a | ||
F-test | |||||||
M | ns | ns | ns | ns | ns | ||
C | ns | * | ** | ** | * | ||
M × C | ns | * | ns | ** | ns | ||
*, ** and ns = Significant at 0.05 level, significant at 0.01 level and not significant, respectively. Means in the same column with different letters are significantly different at p ≤ 0.05 and p ≤ 0.01, as determined by LSD.
plant and fresh storage root yield, but not significant effect on weight of storage roots per plant, starch content and harvest index (
Planting method and cassava cultivar had significant effects on dropping leaf dry weight (DLDW) (
Treatment | Number of storage root per plant | Weight of storage root per plant (kg) | Fresh storage root yield (t∙ha−1) | Starch content (%) | Harvest index |
---|---|---|---|---|---|
Planting method (M) | |||||
Vertical | 10.7 a | 6.1 | 60.6 a | 28.1 | 0.74 |
Horizontal | 8.9 b | 5.3 | 54.3 b | 27.8 | 0.77 |
Cultivar (C) | |||||
Rayong-7 | 10.3 a | 6.7 a | 67.4 a | 28.5 ab | 0.78 ab |
Rayong-11 | 10.8 a | 5.4 ab | 54.6 ab | 28.9 a | 0.75 bc |
Rayong-72 | 7.7 b | 5.3 ab | 49.7 b | 26.4 b | 0.81 a |
Huaybong-80 | 10.1 ab | 4.8 b | 55.0 ab | 29.4 a | 0.70 c |
E-dum | 10.2 a | 6.1 ab | 60.4 ab | 26.6 b | 0.72 c |
F-test | |||||
M | * | ns | * | ns | ns |
C | * | * | * | * | ** |
M × C | ns | ns | ns | * | ns |
*, ** and ns = Significant at 0.05 level, significant at 0.01 level and not significant, respectively. Means in the same column with different letters are significantly different at p ≤ 0.05 and p ≤ 0.01, as determined by LSD.
Treatment | Dropping leaf | Relative water content (%) | ||||
---|---|---|---|---|---|---|
Dry weight (t∙ha−1) | PercentageA | 60 | 80 | 110 | ||
DAP | ||||||
Planting method (M) | ||||||
Vertical | 1.88 a | 44.9 | 87.5 | 81.0 b | 89.6 | |
Horizontal | 1.48 b | 41.9 | 85.6 | 58.7 a | 89.4 | |
Cultivar (C) | ||||||
Rayong-7 | 1.78 a | 46.7 a | 87.1 | 82.6 | 88.4 | |
Rayong-11 | 1.78 a | 44.2 a | 87.1 | 84.8 | 89.1 | |
Rayong-72 | 1.61 ab | 46.4 a | 84.7 | 81.8 | 90.3 | |
Huaybong-80 | 1.92 a | 47.2 a | 86.1 | 82.5 | 90.5 | |
E-dum | 1.33 b | 32.4 b | 87.9 | 85.1 | 89.1 | |
F-test | ||||||
M | ** | ns | ns | * | ns | |
C | * | * | ns | ns | ns | |
M × C | * | ns | ns | ns | ns | |
*, ** and ns = Significant at 0.05 level, significant at 0.01 level and not significant, respectively. Means in the same column with different letters are significantly different at p ≤ 0.05 and p ≤ 0.01, as determined by LSD; APercentage of dropping leaf dry weight to total leaf dry weight (dropped leaf + retained leaf on plant.
dropping leaf dry weight with horizontal planting (data not shown). Planting method did not have significant effects on dropping leaf percentage, but had significant effects among cassava cultivars (
Planting methods and cassava cultivars had significant effects on nitrogen uptake of storage roots, but not significant effect on nitrogen uptake of stem and leaf (
Treatment | Nitrogen (kg∙ha−1) | Phosphorus (kg∙ha−1) | Potassium (kg∙ha−1) | ||||||
---|---|---|---|---|---|---|---|---|---|
Root | Stem | Leaf | Root | Stem | Leaf | Root | Stem | Leaf | |
Planting method (M) | |||||||||
Vertical | 60.1 a | 47.0 | 88.8 | 25.3 a | 28.3 | 7.9 | 273.8 a | 73.8 | 30.1 |
Horizontal | 54.3 b | 38.9 | 80.2 | 22.6 b | 24.2 | 7.1 | 249.6 b | 73.6 | 28.2 |
Cultivar (C) | |||||||||
Rayong-7 | 74.7 a | 45.3 | 85.5 | 27.9 | 35.8 a | 6.9 ab | 316.0 | 54.7 b | 35.7 a |
Rayong-11 | 59.9 ab | 38.8 | 95.9 | 25.4 | 37.1 a | 9.2 a | 283.8 | 111.1 a | 33.9 ab |
Rayong-72 | 45.9 b | 38.8 | 74.1 | 20.7 | 19.0 b | 6.5 b | 223.4 | 58.8 a | 24.3 c |
Huaybong-80 | 55.6 b | 48.5 | 72.1 | 22.1 | 21.0 b | 5.6 b | 227.0 | 96.2 a | 25.3 bc |
E-dum | 49.9 b | 41.1 | 94.8 | 23.4 | 18.4 b | 9.0 a | 258.1 | 48.2 b | 26.2 bc |
F-test | |||||||||
M | * | ns | ns | ** | ns | ns | * | ns | ns |
C | * | ns | ns | ns | ** | * | ns | ** | * |
M × C | ns | * | * | ns | * | * | * | ns | ** |
*, ** and ns = Significant at 0.05 level, significant at 0.01 level and not significant, respectively. Means in the same column with different letters are significantly different at p ≤ 0.05 and p ≤ 0.01, as determined by LSD.
planting. Irrespective of phosphorus, the data shows that planting method had significant effects on phosphorus uptake of storage roots, but not significant effect on phosphorus uptake of stem and leaf (
Planting methods did not have significant effects on N and P removal of cassava but showed significant effects on K removal (
Treatment | Nitrogen (kg∙ha−1) | Phosphorus (kg∙ha−1) | Potassium (kg∙ha−1) | |||
---|---|---|---|---|---|---|
RemovedA | ReturnedB | RemovedA | ReturnedB | RemovedA | ReturnedB | |
Planting method (M) | ||||||
Vertical | 195.8 | 18.2 a | 61.5 | 3.8 a | 377.7 a | 5.0 a |
Horizontal | 172.6 | 15.3 b | 53.9 | 3.1 b | 342.6 b | 3.9 b |
Cultivar (C) | ||||||
Rayong-7 | 205.4 | 18.6 a | 70.7 a | 3.5 | 396.9 | 4.2 b |
Rayong-11 | 194.7 | 19.2 a | 71.6 a | 3.2 | 428.9 | 5.8 a |
Rayong-72 | 158.9 | 14.1 b | 46.2 b | 3.5 | 306.5 | 3.8 b |
Huaybong-80 | 176.2 | 13.4 b | 48.7 b | 3.2 | 348.5 | 5.7 a |
E-dum | 176.1 | 18.4 a | 51.2 b | 3.5 | 320.5 | 2.7 c |
F-test | ||||||
M | ns | ** | ns | ** | * | * |
C | ns | ** | ** | ns | ns | ** |
M × C | * | ** | ns | * | * | ns |
*, ** and ns = Significant at 0.05 level, significant at 0.01 level and not significant, respectively. Means in the same column with different letters are significantly different at p ≤ 0.05 and p ≤ 0.01, as determined by LSD; AN-removed in storage root, stem and leaf (uptake) at harvest; BN-returned in dropping leaf (uptake) into the soil during cropping season.
returning, cultivar HB-80 gave maximum P returning with vertical planting, while cultivar E-dum gave the highest P returning with horizontal planting method (data not shown).
Vertical planting gave significantly higher fresh storage root yields than those of horizontal planting method. This was due to the fact that vertical planting produced higher above ground biomass. The present findings are in agreement with those of several investigators [
The results of the vertical planting gave significantly higher number of storage roots per plant than those of horizontal planting. In contrast, vertical and horizontal planting methods did not show any significant effects with respect to number of storage roots per plant [
In the present experiment, vertical and horizontal planting did not show any significant effects on harvest index (HI). This contrasts with previous studies, vertical planting showed significantly higher HI than those of horizontal planting [
At harvest, cassava had removed the greatest quantities of N in the leaf, the stem and K in the storage roots. Similar results were observed for N, P and K removal quantities as reported by [
Cassava was planted in October, in late rainy season, and the crop experienced drought in February-March for 45 days. Vertical planting methods produced the fresh storage root yields (60.6 t∙ha−1) significantly higher than those of horizontal planting (54.3 t∙ha−1) in the present experiment. The storage root yields range from 49.7 - 67.4 t∙ha−1, depending on the cassava cultivars. The cassava cultivar RY-7 gave maximum fresh storage root yields in the present study. Irrespective of nutrient removal, vertical planting removed N, P and K higher than those of horizontal planting. N removal ranges from 159 - 205 kg, 46 - 72 kg for P and 307 - 429 kg for K per hectare, depending on cassava cultivar. Regardless of nutrient removal in plant part, N removed maximum quantities in the leaf, P in the stem and K in the storage roots in the present experiment.
Polthanee, A. and Wongpichet, K. (2017) Effects of Planting Methods on Root Yield and Nutrient Removal of Five Cassava Cultivars Planted in Late Rainy Season in Northeastern Thailand. Agricultural Sciences, 8, 33-45. http://dx.doi.org/10.4236/as.2017.81003