result in larger and more diverse populations of pollinators around those crops. Even though the addition of companion plantings to crops has been known to increase insect diversity, further research is needed to determine if crop yield can also be
John E. Montoya Jr., Michael A. Arnold, Juliana Rangel, Larry R. Stein and Marco A. Palma
Dennis M. TeKrony and Dennis B. Egli
Both seed viability and vigor directly affect the performance of seeds planted to regenerate the crop. Although seed quality can influence many aspects of performance (e.g., total emergence, rate of emergence), this presentation will primarily examine the relationship of seed vigor to one aspect of performance - crop yield. Reductions in yield can be indirectly related to low seed vigor if the low vigor seed results in plant populations that are below a critical level. Thus, we investigated the direct effects of seed vigor on yield in the absence of population differences for annual crops that are harvested at three stages; during vegetative growth, early reproductive growth or at full reproductive maturity. Seed vigor affects vegetative growth and is frequently related to yield in crops that are harvested during vegetative growth or during early reproductive growth. However, there is usually no relationship between vigor and yield in crops harvested at full reproductive maturity because seed yields at full reproductive maturity are usually not closely associated with vegetative growth. The use of high vigor planting seed can be justified for all crops; however, to insure adequate plant populations over the wide range of field conditions which occur during emergence.
Donavon Sonnenberg, Patrick A. Ndakidemi, Ambrose Okem and Charles Laubscher
the positive effects of drip irrigation in improving crop yields ( Ertek et al., 2006 ; Sezen et al., 2006 ; Vázquez et al., 2006 ). The global demand for nutrition is on the increase and the only means to meet such demand is to increase crop yield
E.A. Guertal, B.K. Behe and J.M. Kemble
The use of composted waste materials as an alternative source of potting media has received much interest in recent years. Our objective was to incorporate composted, ground poultry litter into a standard greenhouse potting mix, and evaluate the effect of the poultry litter on vegetable transplants grown in the greenhouse and transplanted to the field. Treatments consisted of potting mixes of 100% potting media or 50/50 media/poultry litter. Collards (Brassica oleracea L. var. acephala DC.), broccoli (Brassica oleracea var. italica Plenck.), cabbage (Brassica oleracea L. var. capitata L.) and three tomato (Lycopersicon esculentum Mill.) cultivars were utilized as test crops. A nutrient solution treatment of 8 oz of 8N-11P-7K fertilizer or 8 oz of water was added when transplants were set in the field. Plant weight and nitrogen content were measured weekly during the greenhouse production stage, and final crop yield was recorded at harvest. Any effect from the inclusion of poultry litter in the potting media on cole crop (collards, broccoli, cabbage) transplant dry weight had disappeared by the fourth week of sampling in the greenhouse, and final yield of cole crops was unaffected by either type of potting mix or presence or absence of starter nutrient solution. Dry weight of tomato transplants was not affected by type of potting media. Differences in tomato yield due to type of potting mix were observed, as plots with transplants grown in the 50/50 mix had greater nonmarketable yields (`Bonnie' and `Big Boy'). Yield of `Big Boy' tomato was increased by the addition of starter nutrient solution. It appears that composted, uniformly prepared waste materials are suitable for production of vegetable transplants.
Shuresh Ghimire, Annette L. Wszelaki, Jenny C. Moore, Debra Ann Inglis and Carol Miles
Polyethylene mulch has been used in agriculture for more than 60 years and contributes to crop yield and quality by reducing weed pressure and herbicide use, moderating soil temperature, and conserving soil moisture ( Emmert, 1957 ; Ibarra
Christopher Worden, George Elliott, Bernard Bible, Karl Guillard and Thomas Morris
A composting facility in New Milford, Conn. (NMF), utilizes food-processing residuals, including spent tea leaves, coffee grounds, cocoa shell and cleanings, wastewater treatment sludge from a food ingredients manufacturing plant, and past-expiration processed vegetable products. Materials are composted in aerated, frequently turned windrows under cover. The range of inputs, combined with time constraints on the composting process, has resulted in a variable, immature compost product with a high rate of microbial activity. Users have expressed concern about potential phytotoxicity or nutrient immobilization from using NMF compost. Therefore, research was conducted to determine the influence of cured and uncured NMF compost amendments on potentially sensitive crops with high nutrient requirements. Arugula (Eruca vesicaria) and green bibb lettuce (Lactuca sativa) were grown on two Connecticut organic farm research sites in 1998 and 1999. Both sites have soils classified as coarse loamy over sandy or sandy-skeletal, mixed, mesic, typic, Dystraudepts. Farms differed in the length of time under organic farm management. One farm has been an organic farm since 1988 and consequently has high soil fertility, while the other was a first-year organic farm in 1998, and had relatively low soil fertility. Three amendment types were applied: cured compost, uncured compost, and organic fertilizer (5N-3P2O5-4K2O). Amendment application rates were estimated to provide a comparable range of plant-available nutrients for the amendments and a control without fertilizer. Compost application rates were 3.4, 6.8, 20.2, 35.8, and 71.7 Mg·ha-1 (dry-weight basis) in 1998 and 11.2, 22.4, 44.8, and 89.6 Mg·ha-1 (dry-weight basis) in 1999. Organic fertilizer application rates were 1.34, 2.68, 5.36, 10.72, and 21.44 Mg·ha-1 in 1998 and 1.34, 2.68, 5.38, and 10.72 Mg·ha-1 in 1999. Soil organic matter and nutrients increased with amendment application rate at both locations. Crop yields increased with amendment rate at the new, lower-fertility farm, but yields did not respond to amendments at the older, higher-fertility farm. Yield differences were minor between the uncured and cured compost treatments at both locations. This indicates that either cured or uncured NMF food-processing residual compost can be successfully used as an organic soil amendment for salad green production.
Bryan Hed and Michela Centinari
study confirmed that ELR is an effective tool for reducing crop yield, regardless of the method of application ( Diago et al., 2010 ; Intrieri et al., 2008 ; Tardaguila et al., 2010 ). A reduction in crop level is desirable when it improves balance
James E. Ells, Ann E. McSay, E. Gordon Kruse and Gregory Larson
Squash (Cucurbita pepo L. var. pepo) plants were grown on black polyethylene mulch or on bare ground, with trickle or furrow irrigation, and received only natural rainfall, or natural rainfall plus half or all of the estimated supplemental irrigation water required as determined by an irrigation scheduling program. The squash roots predominate in the upper 6 inches of soil throughout the season, with no less than 60% of the root mass located in this layer. The proliferation of roots increased as they extended horizontally from the vertical center line of the plant from 0 to 24 inches. Neither the irrigation treatments nor black polyethylene mulch had any influence on the pattern of root development. Water stress, however, reduced the size of the root system and the crop yield. Yields were not influenced by either furrow or trickle irrigation on the short rows that were used in this study. However, black polyethylene mulch and full irrigation offered the best chance of maximizing squash yields under the conditions of this study.
Y.L. Grossman and T.M. DeJong
Plant dry matter production is proportional to light interception, but fruit production does not always increase with increased light interception. Vegetative growth potential, the effect of cropping on vegetative growth, light interception and cropping efficiency of a clingstone peach [Prunus persica (L.) Batsch `Ross' on `Nemaguard' rootstock] were assessed in four production systems differing in tree density and training system. The four systems were a perpendicular V (KAC-V) system, a high-density perpendicular V (HiD KAC-V) system, a cordon system, and an open vase system. Vegetative growth potential, assessed on defruited trees, was higher in the cordon system and lower in the open vase system compared to the V systems. Cropping reduced leaf growth on the V and cordon systems and stem growth on the KAC-V and cordon systems. On a ground area basis, the HiD KAC-V system had the highest crop yields and the open vase system had the lowest. The cordon and HiD KAC-V systems intercepted more light and produced more fruit, stem, and leaf biomass than the open vase system. However, the modified harvest increment, the ratio of fruit dry mass to the sum of fruit, leaf, and stem dry mass, was lower in the cordon system than in the other systems. Thus, on this basis, the cordon system was the least efficient. On a trunk cross-sectional area basis, there were no significant differences in fruit production among any of the four training systems. For current year production, crop production per unit ground area is the best measure of economic efficiency. However, when planning the spacing, training and pruning of orchard trees, the most appropriate goal seems to be a system that increases light interception without increasing vegetative growth potential, such as the HiD KAC-V system.
Ramesh R. Sagili, Carolyn R. Breece, Rhonda Simmons and John H. Borden
and queen mandibular gland pheromone have been tested to enhance bee visitation and crop yields with meager success ( Delaplane and Mayer, 2000 ) or no success ( Ellis and Delaplane, 2009 ; Mayer et al., 1989 ; Roper et al., 1990 ; Schultheis et al