Increased Potato Yield Research Articles

Organic Transition Strategies for Vegetable Farms Near Urban Areas

The risk: reward for a transition to organic vegetable farming near urban areas and changes in soil, crop, and economic parameters during transition are poorly understood. A 4-year study was initiated in 2003 at the Ohio State Univ.–OARDC to document the relative advantages of four transition strategies and their effects on major cropping system variables. Soil previously in a vegetable-agronomic crop rotation has been maintained fallow, planted to a mixed-species hay, used in open field vegetable production, or used in vegetable production under high tunnels, transition strategies with a range of management intensity and expected financial return. Each strategy was replicated four times within the overall experimental area. Half of the soil in each strategy unit was amended with composted dairy manure while the remaining soil was unamended. Field vegetable plots have been planted to potato, butternut squash, and green bean. High tunnels have been planted to potato, zucchini, and a fall–spring rotation of beet, swiss chard, mixed lettuce, radish, and spinach. Data describing the outcomes of the strategies in terms of farm economics, crop yield and quality, weed ecology, plant pest and disease levels, and soil characteristics (physical, chemical, biological) have been recorded. Inputs in the high tunnels have exceeded inputs in all other strategies; however, high tunnel production has widened planting and harvesting windows and increased potato yield, relative to open field production. To date, compost application has increased crop yield 30% to 230% and influenced crop quality, based on analytical and human panelist measures. Weed (emerged seedlings, seedbank) and nematode populations also continue to vary among the transition strategies.

Early‐Season Applications of Sulfur Fertilizers Increase Potato Yield and Reduce Tuber Defects

Sulfur recommendations are based on avoiding deficiency. Since S may have additional effects, the objective was to determine whether S fertilizers increase yield and reduce tuber defects. Potato (Solanum tuberosum L.) cultivar Atlantic was treated with wettable sulfur (WS), ammonium sulfate (AS), and ammonium thiosulfate (TS) at 0, 28, 56, 84, and 112 kg S ha−1 applied at planting [in‐furrow (IF)], 11 d later [pre‐emergence (PE)], 11 d after emergence [postemergence (PT)], and at tuber initiation (TI). Separate trials were conducted for each fertilizer and application. Ammonium nitrate and urea were added to AS and TS to equalize N. Yield of U.S. “A” potato was increased 11 to 34% by fertilizers at S rates greater than 56 kg ha−1 at IF, PT, and by AS and WS at TI. These fertilizers applied IF and at TI reduced the incidence of common scab (Streptomyces scabies) on tubers. When applied PT, AS and TS reduced common scab; WS did not. The incidence of black scurf (Rhizoctonia solani) on tubers was reduced when AS and TS were applied PT but not when applied IF and at TI. Pre‐emergence application had no effect. Other tuber characteristics, e.g., specific gravity and vascular discoloration, were unaffected. Plant growth was inhibited by TS applied after emergence but recovered. Yield was increased by S at 56 kg ha−1 applied IF, PT, and at TI except for TS applied at TI. Common scab and black scurf were reduced depending on application timing and fertilizer.

Effect of rainwater harvesting with ridge and furrow on yield of potato in semiarid areas

A new planting pattern for potato production in semiarid areas was designed and tested for enhanced tuber yield and for the benefit of collecting rainwater. This pattern comprised two elements: the ridge mulched by plastic film that acts as the runoff area and the furrow as the infiltration basin or planting area. The conventional planting pattern for potato production in semiarid regions of northwestern China is the opposite with mulched ridges for planting and the furrow as an infiltration zone. The purpose of this study was to examine the effect of the ridge with or without mulching on rainwater harvesting and the response in potato yield and to determine the optimal cross-sectional area of the ridge and furrow. A ratio defined as the width of the ridge to the width of the furrow or the planting area was used to evaluate the cross-sectional area. Three ratios of 0.5, 0.75, and 1.0 were tested under the conditions of mulched ridge, bare earth ridge, and no ridge or flat planting, respectively. No matter what ratio used, the width of the planting belt was the same at 0.6 m. The results showed that for tuber yield, the ridge with the plastic mulching was more effective than the bare earth ridge and that the bare earth ridge was better than flat planting. In the mulched ridges, a ridge width of 0.45 m or a ratio of ridge to furrow of 0.75 led to higher yield than that of ridges with a width of 0.3 and 0.6 m. For the bare earth ridges, the yield in the 0.6 m ridge width was higher than that of the other two ridges. Besides improving potato yield, the mulched ridge and furrow planting had the added advantage of collecting considerable rainwater for soil moisture. In addition, the percentage of small-sized potatoes was low. Therefore, we recommend that the mulched ridge with a ridge width of 0.45 m and a furrow width of 0.6 m as a successful method to increase potato yield in semiarid areas where potato production relies totally on rainwater.

Reactions of some potato genotypes to late blight in Cameroon

Field experiments were conducted in Cameroon in 1995 and 1996 to evaluate reactions of different potato genotypes to late blight. There were significant differences among genotypes for tuber yield, late blight readings and earliness. The application of fungicides significantly increased potato yield but had a non significant effect on the damage due to foliage blight (Phytophthora infestans). The limited effect of fungicide treatment was because the late blight severity was so high that the eight fungicide applications could not provide sufficient level of disease control and/or the persistence rain throughout the growing season might have washed-off the applied fungicide, thus decreasing its effect. There was a significant year effect on the yield. The fifth late blight reading (LB5) was more related to yield than the later readings suggesting that the damage caused by the disease at an earlier stage of plant development contributed most to yield reductions. Several advanced genotypes had similar or superior performance to that of CIPIRA and TUBIRA released in Cameroon in 1992. Key Words: Cameroon, Phytophthora infestans, potato yield, Solanum tuberosum (African Crop Science Journal 2001 9(1): 209-214)

Effect of subsoil tillage in the previous crop year on soil loosening and potato yield performance

Soil compaction under potato rotations can be a common problem in Prince Edward Island. This can be further aggravated by naturally occurring compact subsoils. A study was conducted at eight sites on sandy loam soils in three regions of Prince Edward Island to determine whether the recommended practice of subsoiling the fall prior to the potato crop would improve the physical condition of the soil and result in improved yields. The study found that subsoiling provided only a marginal improvement in soil physical conditions. Soil loosening did not increase potato yield or quality. Key words: Potato, subsoiling, yield response, potato quality

Early growth of six native Australian tree species in windbreaks and their effect on potato growth in tropical northern Australia

A study to examine the early growth of a number of tree species planted in windbreaks and to quantify the benefit of two 30-month-old windbreaks (one with two rows of trees and one with three rows of trees) to the production of potato (Solanum tuberosum L.) was conducted on a farm land in tropical north-eastern Australia. Three Eucalyptus (E. microcorys F. Muell, E. tessellaris F. Muell and E. torelliana F. Muell), two Callistemon (C. salignus Smith and C. viminallis Smith) and two Melaleuca species (M. armillaris Smith and M. linariifolia Smith) were used to form the windbreaks. Tree performance in the windbreaks was evaluated based on the measurements of height, height to the lowest branch, crown length along the row, and number of branches per plant. Potato vegetative growth including plant height, crown size, and leaf length, width (measured at the widest part of the leaf), and number per plant, was measured at ages 2, 4, 6 and 8 weeks.E. microcorys and E. torelliana, showed rapid height and branch growth while retaining low branches and are considered highly suitable for windbreaks. The porosity of the three row and two row windbreaks were 37.2% and 60% respectively at age 30 months. The windbreaks increased potato plant growth in height and leaf number with vegetative plants being tallest at 3 h from the windbreaks. However, the windbreaks had limited effects on leaf length and width. It was found that potato plants grown close to windbreaks yielded more potatoes than those grown at the furthest positions, with the highest production at 3 h. Overall, the windbreaks studied increased potato yield by up to 7.7%.

Short-term effects of crop rotations and wood-residue amendments on potato yields and soil properties of a sandy loam soil

A 3-yr study (1988–1990) was conducted on a Beaurivage sandy loam soil located in St-Lambert, Québec, Canada, to evaluate the short-term effects of crop rotations and organic amendments on soil properties and potato yields (Solanum tuberosum, L.). Treatments consisted of yearly fall rye (Secale cereale, L.) as a green-manure cover crop, barley (Hordeum vulgare, L.) grown every 3-yr in potato crop rotation, partially humified bark residues and fresh tree clippings applied once at 100 m3 ha−1 in the beginning of the experiment, and continuous potato in monoculture used as check. Fertilizer rates were applied at 150, 100, 160 and 40 kg ha−1 rates for N, P2O5, K2O5 and Mg, respectively. Results indicated that more rapid changes of soil C content were observed with ligneous material incorporation than with fall rye and barley residue additions. Compared with fresh tree cuttings, partially humified bark induced rapid changes in soil organic C and cationic exchange capacity (CEC). A temporary soil structural stability improvement was observed in 1989 under fall rye cover crop. However soil bulk density increased significantly (P < 0.05) in these plots in 1990, and this was also related to low potato yields. Barley residues and ligneous amendments significantly improved soil water content during the critical flowering stage, and this increased potato yields and specific gravity (P < 0.05). In general, soil amendment would improve potato yields and quality through improved soil water content on a short-term. Key words: Barley, rye, rotation, cover crop, ligneous amendments, potato yields, soil physical and chemical properties

Field evaluation of foliar and soil insecticides for the control of Aphis gossypii Glover (Homoptera: Aphididae) on potatoes in Kenya

Field evaluation showed oxydemeton methyl 25% E.C. at 0.6 kg a.i./ha and dimethoate 40% E.C. at 0.74 kg a.i./ha to be more effective than cypermethrin 40% E.C. at 0.25 kg a.i./ha, decamethrin 2.5% E.C. at 0.03 kg a.i./ha, endosulphan 35% E.C. at 0.8 kg a.i./ha and profenofos 50% E.C. at 0.74 a.i./ha in the control of apterae on potatoes. Disulfoton 10G at 1.6 k0g a.i./ha and carbofuran 10G at 5.2 kg a.i./ha were superior to oxamyl 10G at 5.2 kg a.i./ha and terbufos 5G at 2.6 kg a.i./ha applied in the furrow at planting for the control of aphids. Although these insecticides gave good control of apterae, the alate population in the treated plots varied from significant reduction to no reduction. All the insecticides tested did not significantly increase potato yield, although mean yields were increased.

Increased Potato Yields by Treatment of Seedpieces with Specific Strains of Pseudomonas fluorescens and P. putida

Increased Potato Yields by Treatment of Seedpieces with Specific Strains of Pseudomonas fluorescens and P. putida

Irrigation as a Practical Means to Control Potato Common Scab (Streptomyces scabies)

SUMMARYIrrigation in 1970 at Gleadthorpe E.H.F. increased potato yields and, when given from the time of tuber initiation, controlled common scab on the susceptible cultivars King Edward, Majestic and Record. Pentland Crown had little scab with or without irrigation. It was the driest May and June since 1934 and there was already a soil moisture deficit (S.M.D.) of 1.8 in. (46 mm) at tuber initiation by King Edward and when water was first given. Subsequently irrigation at 0.6 in. (15 mm) or 0.8 in. (20 mm) S.M.D. was more effective than 1.5 in. (38 mm) or 2.25 in. (57 mm) S.M.D. in controlling scab, and more effective at 0.6 in. S.M.D. when maintained for 4 wk than for 2 wk.Irrigation at 0.6 in. S.M.D. for 4 wk increased the weight of premium (Table Grade) potatoes by respectively, 16, 12, 13 and 12 tons/acre (40, 30, 32.6 and 30 t/ha) for King Edward, Majestic, Record and Pentland Crown.Tubers developed slowly in unirrigated plots both in volume and in the rate that eyes separated. King Edwajd produced more tubers per plant than Majestic; irrigation did not increase tuber numbers.

Effects of magnesium on cereals, potatoes and leys grown on the ‘continuous cereals’ site at Woburn

SummarySymptoms of magnesium deficiency and take-all disease occurred during 1967 in wheat grown for the second year in succession on the ‘Classical’ cereal site at Woburn. Magnesium fertilizers, which cured the deficiency symptoms and increased wheat yields in 1968 and 1969, had no effect on take-all. Leaves from crops severely attacked by take-all contained less nitrogen and potassium than leaves from unattacked plants but not less magnesium. In 1969 magnesium fertilizer did not increase yields or affect takeall of spring barley on the site but, in contrast to 1968, increased potato yields. Magnesium fertilizer improved the establishment of clover, especially on soil containing least magnesium.Soil analyses show a tenfold decline in exchangeable Mg since 1888. Losses were most from soil given ammonium sulphate and more from the site where wheat was long grown than where barley was. Differences in soil magnesium did not explain large differences in yields of potatoes or leys between blocks of the experiments.

Long term effects of preplant fumigation of potato fields

The application of nematicides resulted in increased potato yields, and populations ofPratylenchus penetrans were lower for 3 years after application; but longevity of benefits of fumigating potato fields varied with the kind and amount of nematicide, application methods and with growing conditions after fumigation. Fumigation of two fields in the fall of 1965 with Vorlex, Telone, D-D, and mixtures of chloropicrin with Telone or D-D resulted in 70% to 90% control of the meadow nematode,P. penetrans, after two crops in one field, and 50% to 70% control after three crops in another. Yield increases of Kennebec potatoes averaged 42% and 16% in successive crops in the first field and yield increases of Katahdin potatoes averaged 13%, 22% and 16% in three successive crops in the other field. Fumigation resulted in 30 to 70% less vascular browning in tubers in the first two crops but there was no effect in the third crop. There was no effect on black scurf in any crop. Root injury varied proportionally with populations ofP. penetrans in roots in 1967. Populations ofP. penetrans regained injurious levels in three other fields after one crop when abundant root growth in moist 1967 followed spring fumigation with Telone and D-D. Under poor conditions for sealing of the soil following fumigation in the spring of 1968, counts ofP. penetrans collected at different soil depths after fumigation showed excellent kill below 3 inches and poorer kill in the upper 2 inches of soil.

Experiments comparing the effects on yields of potatoes of three methods of applying three amounts of NPK fertilizer and the residual effects on following winter wheat

1. Seven experiments with main-crop potatoes on heavy soils from 1962–5 measured yields from 0, 5, 10 or 15 cwt/acre of 13–13–20 fertilizer; (1) broadcast and worked into the soil by seed bed preparations; (2) broadcast on the final seed bed; (3) placed in bands 3 in. from the seed centre. Wheat followed the potatoes and was manured with 0, 5, or 10 cwt/acre (of the equivalent) of 13–13–20 fertilizer, in all combinations with the four amounts of, and the three ways of applying, the fertilizer given for the potatoes.2. Fertilizer greatly increased potato yields and 15 cwt/acre of 13–13–20 was justified, provided it was broadcast. Both methods of broadcasting gave similar yields with 5 or 10 cwt/acre, but working the fertilizer into the seed bed was usually the better method with 15 cwt/acre of the fertilizer. Placing in bands beside the seed was the best method in four experiments with 5 cwt, in two with 10 cwt, but never with 15 cwt/acre of fertilizer.3. Yields of green wheat, and of grain and of straw, were increased by residues of fertilizer applied for the potatoes, but were increased much more by freshly applied fertilizer. The residues increased wheat yields by the same amount as one quarter as much freshly applied fertilizer. The residues had smallest effects when the winter rainfall was largest, and were the same however the fertilizer had been applied.