Cool-season Crop Research Articles

Potential Impact of Climate Change Trends on Wheat Production and Mitigation Strategies in Afghanistan

Climate change is here and continues unabated. It is expected to affect different biological processes differently. Afghanistan has a varied climate profile and depends heavily on wheat, the staple food of its 30 million people. The irrigated wheat occupying about 1.35 million hectare and contributes major chunk of wheat to national granaries compared to rainfed wheat which is more opportunistic with an unpredictable and uncertain share in national harvest. Previous decades have already seen a reduction of up to 100 mm wheat season rainfall and more reductions are estimated by 2050. Also, wheat which is a cool season crop and is also estimated to face higher temperatures by up to 5 degree Celsius across several provinces in the country. The study predicts variable impact of the estimated changes on the productivity of irrigated and rainfed wheat in Afghanistan.

Integrating a complex rotation with no-till improves weed management in organic farming. A review

No-till practices are restoring and protecting soil health and are considered critical for achieving sustainability of global agriculture. Organic producers in the USA would like to no-till, but are concerned about managing weeds without tillage. In conventional agriculture, no-till improves weed management in diverse rotations when crops are arranged in 2-year intervals of cool season and warm season crops. A similar approach with organic rotations may enable producers to also accrue the weed management benefit of no-till in organic farming along with restoring soil health. Here, we review the benefits gained for weed management when a complex rotation is integrated with continuous no-till. The complex rotation included 3 years of a perennial legume and 6 years of annual crops arranged in 2-year intervals of warm season or cool season crops. The no-till, complex rotation can (1) reduce weed emergence 3- to 4-fold in some annual crops; (2) delay weed emergence 2 to 4 weeks; (3) reduce yield loss due to weed interference; (4) suppress invasion of dandelion into cropland; and (5) enhance soil restoration, improve nutrient cycling, and increase soil porosity. Furthermore, perennial red clover can be converted to no-till cropland with fall mowing; thus, organic producers can include a perennial legume in a no-till rotation. The complex rotation increases the impact of no-till on weed seed decay in soil and provides numerous opportunities for cover crops to replace tillage for controlling weeds. These benefits suppress weed growth and interference such that organic producers may be able to continuously no-till in their farming systems, thus accruing restoration of soil health and long-term sustainability gained with no-till.

Effect of thermal processing and chemical preservatives on the physicochemical and phytochemical parameters of carrot juice

Carrot is an excellent source of β-carotene and antioxidants.. Carrot is a cool season crop and during the harvesting season, large quantities get spoiled due to excess production. So a long term preservation method is required that could be useful to prevent spoilage of carrot such that it could be consumed in off seasons as well. Keeping in view the nutrirional and therapeutic value of carrots carrot, juice was processed and treated with different chemical additives and tested for various physichochemical, phytochemical characteristics and antioxidant activity. At the end of storage period of six months, KMS treated samples were found to retain the maximum nutritional quality. There was significant (p≤0.05) increase in the shelf stability of the chemically preserved juices than the thermally treated samples.

Genetic approaches for breeding heat stress tolerance in faba bean (Vicia faba L.)

Vicia faba L. (faba bean) is an important legume and is cultivated essentially as a cool-season crop. Changes in sowing dates and lack of precipitation expose faba bean crop to drought and heat stresses. The gradual rise in global temperatures owing to climate change is likely to exacerbate the detrimental effects of hot and dry climatic conditions on faba bean cultivation. High temperature stress is particularly damaging to faba bean during the flowering period, when the viability of pollen is critical for successful reproduction. Recent studies have shown that maintenance of protein homeostasis through synthesis of heat shock proteins plays a key role in the heat response of plants. To date, there has been no significant work linking the heat response of faba bean to the repertoire of its heat shock proteins. While quantitative trait loci have been identified for resistance against biotic stresses in faba bean, there is no parallel success with abiotic stresses in this species. Programs aiming at genetic improvement of the heat/drought resistance of this crop by both conventional breeding and molecular breeding methods are hampered because of the large and majorly ill-analyzed genome of faba bean plants. Likewise, molecular and biotechnology-related tools are poorly developed for faba bean; as a result, the fruits of transgenic research developed with model plant species are not reaching this crop. While specifically discussing the prospects for the genetic improvement of faba bean against heat and drought stresses, we highlight the areas of research which need to be strengthened on faba bean.

Turnip mosaic virus: potential for crop losses in the grain belt of New South Wales, Australia

The potential of Turnip mosaic virus (TuMV) to infect and damage cool season crops in the grain belt of New South Wales, Australia, was investigated by serological tests on 24,689 dicot weed, grain, and forage specimens from 1999 to 2007 and infectivity/pathogenicity tests with six isolates. Natural infection by TuMV was common in Brassicaceae weeds. Infected grain crops included mustard (Brassica juncea), field pea (Pisum sativum), chickpea (Cicer arietinum), and coriander (Coriandrum sativum). Forage (turnip, Brassica rapa) was also infected. None of 9,816 canola (Brassica napus, at least 19 cultivars) or 1,967 faba bean (Vicia faba, three cultivars) plants were infected. Six isolates from weeds, mustard, and chickpea were inoculated on a range of weed and crop species including four B. napus pathotype differential lines. Inoculated Brassicaceae weeds, mustard, field pea cv. ‘Cressy Blue’, coriander, Chinese cabbage (B. rapa), and forage turnip (B. rapa) were usually infected. Field pea cv. Dundale and radishes (Raphanus sativus) were infected infrequently. Symptoms were severe in mustard, forage turnip, chickpea, and field pea. The reportedly susceptible canola cv. ‘Outback’ displayed only variable infectivity and mild symptoms for five isolates and no infectivity for one isolate. Faba bean, field pea cv. ‘Excell’, and two B. napus differentials appeared to be non-hosts. The results suggest that TuMV strains naturalised in Brassicaceae weeds in NSW in 1999–2007 could damage mustard, field pea, and forage turnip, but not canola or faba bean. These NSW strains appeared to be distinct from strains that damage canola in Europe, North America, and Asia.

A cultural system to reduce weed interference in organic soybean

AbstractOrganic producers are seeking alternative tactics for weed control, so that they can reduce their need for tillage. In this study, we examined cultural strategies for controlling weeds during the transition from a cool-season crop to soybean. The study was arranged as a two-way factorial, with factors being choice of cool-season crop and tillage treatments. The cool-season crops were either spring wheat harvested for grain or an oat–pea mixture harvested for forage. Five tillage treatments, ranging from intensive tillage to no-till, were established following each cool-season crop. Two tillage treatments included the cover crops, oat plus oilseed radish. Soybean was planted the following growing season. Each soybean plot was split into two subplots: weed-free and weed-infested. A cultural system comprising oat/pea as a preceding crop with no-till and cover crops reduced weed biomass in soybean 63% compared to intensive tillage. Reduced weed biomass resulted because of delayed weed emergence and lower weed community density. Consequently, soybean yielded 14% more in this treatment than with the intensive tillage treatment when weeds were present. Weed community composition also differed between the two systems; horseweed and field dandelion were prominent in no-till, whereas common lambsquarters, redroot pigweed and buffalobur were prevalent in the tillage control. Other treatments did not control weeds better than intensive tillage. A cultural system approach may minimize the need for tillage during the interval between cool-season crops and soybean.

Merging Physiological and Genetic Approaches to Improve Abiotic Stress Resistance

There is ample evidence for global warming and resulting climate change. To sustain food production in view of climate change, we need to improve resistance to abiotic stresses in commercially desired cultivars. Using potato as an example, a strategy is illustrated for such improvement by merging physiological and genetic approaches. Potato (Solanum tuberosum L.) is a cool-season crop, cultivated in the temperate zone in North America, Europe, and the highlands of South America, Africa, and Asia. In these areas, frost is often a major factor limiting potato production. Climate change models predict erratic weather patterns including more severe and untimely frost episodes. Cultivated potatoes are highly frost sensitive and are often killed when tissue temperatures fall below −3°C. Several wild potato species are frost tolerant. These species carry two desired traits: 1) They can survive temperatures as low as −6°C while growing under normal conditions (NAFT), and 2) they are able to acclimate in response to chilling temperatures and increase frost tolerance and survive at temperatures as low as −12°C (CAC). These two important traits are lacking in cultivated potatoes. We have demonstrated that NAFT and CAC are genetically distinct traits that must be selected for individually and combined in a desired genotype. By precise screening for both NAFT and CAC, we have been able to select frost-hardy clones of potato that also carry commercially desired traits. This progress was made possible by understanding the physiological and biochemical mechanisms of frost survival and cold acclimation. We have shown that: 1) plasma membrane ATPase is an important site of cellular response to temperature stress, and this response appears to be mediated by changes in cellular/membrane calcium and changes in membrane lipid composition; 2) specific lipid composition changes occur in the plasma membrane that allow a plant to acclimate to cold and increase freezing tolerance, and an increase in the degree of unsaturation of specific lipids is important in this acclimation process. We have further shown that these changes in lipid are associated with an increased expression of Δ9 desaturase gene during cold acclimation; 3) calcium can mitigate the impact of heat, cold, and salinity on potato. In addition to NAFT and CAC, freezing avoidance is an important trait for plant survival. We have been able develop frost-hardy carrot hybrids by combining freezing tolerance in the top with freezing avoidance in the root. Taken together, our studies provide a systematic approach to improving abiotic stress resistances of crop plants and suggest strategies for developing production practices to mitigate the impact of abiotic stresses in a changing climate scenario.

Differential Response of Cysteine-deficient Lentil (<i>Lens culinaris</i> Medik.) Mutants Impaired in Foliar O-acetylserine(thiol)-lyase Expression

Lentil is a cool-season pulse crop, rich in protein but deficient in two sulphur-containing amino acids cysteine and methionine. Due to low genetic variability in existing germplasm, induced mutagenic technique has been adopted in lentil, and two mutant lines exhibiting poor growth and low dry weight were isolated in M 2 -mutagenized (0.10% and 0.15% EMS, 6 h) population of variety L 414. Further analysis revealed that plants from both mutant lines were highly deficient in seed cysteine (Cys) content, and thus, were tentatively designated as cysLc1 and cysLc2 mutants. Mutant plants were advanced to M 3 generation. Biochemical analysis through cysteine synthesizing pathway in leaves revealed that activity of serine acetyl transferase (SAT) was normal in both the mutant progenies but both were highly deficient in foliar O -acetylserine(thiol)-lyase (OAS-TL) activity. Transcriptomic analysis by qRT-PCR confirmed normal expression of SAT in both mutants but revealed differential expressions of two OAS-TL isoforms; OAS-TL 1 isoform was not detectable in cysLc1 mutant while expression of OAS-TL 2 isoform was totally repressed in leaves of cysLc2 mutant. Genetic studies and test of allelism pointed out that both the mutants were recessive and were complementing with each other to produce normal in F 1 and normal along with mutant plants in F 2 progeny. The progeny plants exhibiting normal phenotype showed normal mRNA transcripts of both OAS-TL isoforms. Being stable and self-fertile, the mutants will give vital clues in genetic basis of thiol-metabolic network of lentil crops.

Effect of Pre-treatments on Physical and Sensory Qualities of Dehydrated Carrot Slices

Carrot is a popular cool season crop grown throughout India. It is used as raw as well as cooked form. The preservation methods such as dehydration, canning, and pickling can be successfully adopted to preserve carrot for off-season. Dehydrated carrot in the form of grating can be used in the preparation of halwa, discs made in to chips. Carrot is rich source of vitamin A and is a seasonal crop. To make available in the off season and to exploit the nutritive value of carrot it is necessary to convert into various value added products. Among the different methods of preservation, dehydration is one of the best and cheapest method of preservation. In this regard, a study was conducted to prepare dehydrated carrot slices. The experiment was conducted in completely randomized block design with seven treatments and three replications. The various physical parameters like recovery, time taken for drying, rehydration ratio, dehydration ratio, reconstitution ratio and organoleptic evaluation were carried out. Among the different treatments carrot slices dehydrated without any pretreatment taken minimum time for dehydration (15.10 hrs) whereas carrot slices dehydrated with blanching for 2 minutes + steeping in 40° Brix syrup + 6% salt for 2 hours had taken maximum time for dehydration (18.45 hrs). The highest recovery and lowest dehydration ratio were noticed in carrot slices dehydrated with blanching for 2 minutes + steeping in 40° Brix syrup + 6% salt for 2 hours. The rehydration ratio was found higher (5.04) in the slices steeped 0.75 percent KMS for 2 hours whereas the lowest rehydration ratio (2.59) was found in carrot slices blanched for 2 minutes + steeped in 40° brix syrup + 6% salt for 2 hours. The highest reconstitution ratio (0.57) was found in slices blanched for 2 minutes + steeped in 40° brix syrup+ 6% salt for 2 hours. Higher scores for colour and appearance (4.55), taste (4.43) were recorded in the slices blanched for 2 minutes + steeped in 40° brix syrup + 6% salt for 2 hours (T6) whereas highest score for texture (4.46) and overall acceptability (4.55) were recorded in the slices blanched for 2 minutes + steeped in 300 brix syrup + 6% salt for 2 hours which was on par with T6. It indicated that sugar and salt treatment blends improved the organoleptic qualities (colour, taste and overall acceptability) of the product.

무의 질소 시비량에 따른 생육량 추정 모델식 개발

최근 30년 동안 우리나라의 평균온도와 겨울철 온도가 각각 <TEX>$0.7^{\circ}C$</TEX>와 <TEX>$1.4^{\circ}C$</TEX>가 상승하였고 지속적으로 상승할 것으로 예측된다. 무는 매우 중요한 작물로 온난화에 따른 생육 모델 연구는 중요하다. 본 실험은 기상 이변에 따른 무의 생육량을 추정하기 위하여 정식시기와 질소 시비량을 다르게 처리하여 시험하였다. 파종시기는 4월 24일부터 5월 22일까지 14일 간격으로 3회에 걸쳐 실시하였고, 질소 시비량은 표준시비량의 0.5, 1.0, 2.0배 수준으로 3처리를 하였다. 그 결과, 무 파종 후 2개월째 생육은 4월 24일 처리구가 5월 8일과 22일 처리구보다 지상부 생체중이 높게 나왔다. 수확량 예측을 위한 생육 모델식은 질소 시비량별 GDD에 따른 지하부 건물중은 0.5N 처리구에서는 Y = 84.66 / (1+exp (-(GDD - 790.7) / 122.3)) (<TEX>$r^2$</TEX> = 0.92), 1.0N 처리는 Y = 100.6 / (1+exp (-(GDD - 824.8) / 112.8))(<TEX>$r^2$</TEX> = 0.92), 2.0N 처리는 Y = 117.7 / (1+exp (-(GDD - 877.7) / 148.5)) (<TEX>$r^2$</TEX> = 0.94) 로 나타낼 수 있었다. 구축된 모델식에 생육데이터를 사용하여 검정한 결과를 보면 기울기가 1.05-1.12로 다소 높게 추정하였지만 모델식으로 적용하는 것에는 무리가 없는 것으로 나타났다. 따라서 봄무 생산량 예측 시 GDD를 사용하여 수확량을 예측할 수 있을 것으로 사료되었다. The average annual and winter ambient air temperatures in Korea have risen by 0.7 and <TEX>$1.4^{\circ}C$</TEX>, respectively, during the last 30 years. Radish (Raphanus sativus), one of the most important cool season crops, may well be used as a model to study the influence of climatic change on plant growth, because it is more adversely affected by elevated temperatures than warm season crops. This study examined the influence of transplanting time, nitrogen fertilizer level, and climate parameters, including air temperature and growing degree days (GDD), on the performance of a radish cultivar 'Mansahyungtong' to estimate crop growth during the spring growing season. The radish seeds were sown from April 24 to May 22, 2012, at internals of 14 days and cultivated with 3 levels of nitrogen fertilization. The data from plants sown on April 24 and May 8, 2012 were used for the prediction of plant growth as affected by planting date and nitrogen fertilization for spring production. In our study, plant fresh weight was higher when the radish seeds were sown on <TEX>$24^{th}$</TEX> of April than on <TEX>$8^{th}$</TEX> and <TEX>$22^{nd}$</TEX> of May. The growth model was described as a logarithmic function using GDD according to the nitrogen fertilization levels: for 0.5N, root dry matter = 84.66/(1+exp (-(GDD - 790.7)/122.3)) (<TEX>$r^2$</TEX> = 0.92), for 1.0N, root dry matter = 100.6/(1 + exp (-(GDD - 824.8)/112.8)) (<TEX>$r^2$</TEX> = 0.92), and for 2.0N, root dry matter = 117.7/(1+exp (-(GDD - 877.7)/148.5)) (<TEX>$r^2$</TEX> = 0.94). Although the model slightly tended to overestimate the dry mass per plant, the estimated and observed root dry matter and top dry matter data showed a reasonable good fit with 1.12 (<TEX>$R^2$</TEX> = 0.979) and 1.05 (<TEX>$R^2$</TEX> = 0.991), respectively. Results of this study suggest that the GDD values can be used as a good indicator in predicting the root growth of radish.

Impact of corn residue on yield of cool-season crops

AbstractSynergy between dry pea and corn can reduce the density of corn needed for optimum yield. Lower crop density may accrue an additional benefit, as after-harvest residues of corn lying on the soil surface can reduce yield of crops planted the next year. This study evaluated impact of corn residue levels on growth and yield of three cool-season crops in no-till. Corn was grown at two densities, 52,000 and 73,000 plants ha−1, leading to after-harvest residue levels designated as low and high residue. Residue quantity on the soil surface differed by 21%. Controls were included for each residue level by burying residue with tillage. Spring wheat, dry pea and red clover were planted the following year. Grain yield of spring wheat and dry pea and forage yield of red clover were reduced 13–33% by residue on the soil surface. However, yield of cool-season crops were 10–18% higher in the low-residue treatment compared with high residue. Furthermore, yield loss because of weed interference in spring wheat and red clover was greater with high residue. Of the three crops, spring wheat was the least affected by corn residue on the soil surface. One contributing factor to lower yield with high residue was reduced crop seedling establishment. Producers may be able to reduce the negative impact of corn residue on following crops in no-till systems by using synergistic crop sequences in the rotation.

Implementation of Best Management Practices to Reduce Agricultural Total Maximum Daily Loads in the Calleguas Creek and Santa Clara River Watersheds: A Case Study of Water Contaminant Mitigation in California

Agriculture is a major industry in California, with cool-season crops grown along the state’s coasts, warm-season crops grown in the hot deserts, and many temperate crops grown in the state’s valleys. In coastal communities such as Ventura County, the Calleguas Creek and the Santa Clara River watersheds have 50,000 and 60,000 irrigated acres of farm crops, respectively. These watersheds are considered impaired by nutrients, salts, pesticides, and other agricultural contaminants. Mitigation of chemical and sediment runoff through grower-implemented best management practices (BMPs) is therefore one of the highest priorities in the Los Angeles Regional Water Quality Control Board Basin Plan. A 3-year project was designed to assist Ventura County growers in meeting regional water quality objectives. The University of California Cooperative Extension Ventura County and the University of California, Riverside, collaborated with the Ventura County Resource Conservation District and the Ventura County Agricultural Irrigated Lands Group (VCAILG) to address three project goals: increase grower and landowner understanding of local agricultural water quality issues; identify gaps or deficiencies in current management practices in agricultural operations; and reduce the contribution of nutrients, pesticides, and other pollutants to impaired water bodies. To achieve these goals, 469 surveys of agricultural water quality management practices were collected to assess the extent of current adoption of BMPs. Over 160 growers who farm more than 14,000 acres that drain into Calleguas Creek and 7,000 acres that drain into the Santa Clara River watersheds were assisted. Using the survey, growers developed site-specific farm water quality plans and received on-farm recommendations for BMPs. Additionally, 12 water quality educational programs, “including demonstrations of successful BMPs,” were developed and more than 2500 copies of educational materials published by the University of California, the Resource Conservation District, and the Natural Resources Conservation Service of the U.S. Department of Agriculture were distributed at on-farm visits, workshops, and other grower events. The project resulted in improved understanding, by growers and landowners, of water quality issues and significantly increased the implementation of appropriate on-farm BMPs to protect water quality. Nearly 100 new BMPs primarily aimed at managing erosion, sediment movement, and irrigation runoff were identified and documented through annual reassessments for more than 8000 acres draining into Calleguas Creek. A total of 518 people attended the educational programs, and over 90% of participants who completed evaluations rated the programs highly. In the final year of the project, 75% of attendees indicated they plan to implement new BMPs within the next 5 years, especially in the areas of irrigation, erosion, and pest management.

Growing Potatoes in the Florida Home Garden

The Irish potato is a cool-season crop. A recently grown and harvested potato exhibits different flavor profiles from one that has been in storage or on a grocery shelf for an extended period. For example, in storage, the starches in potatoes convert to sugars, resulting in a less desirable texture and taste. “New” potato flavor can be achieved in the home garden by following a few growing recommendations. This 9-page fact sheet was written by Christian T. Christensen, Libby R. Rens, Jeffrey E. Pack, Lincoln Zotarelli, Chad Hutchinson, Wendy Dahl, Doug Gergela, and James M. White, and published by the UF Department of Horticultural Sciences, April 2013.&#x0D; http://edis.ifas.ufl.edu/hs183

Impact of climate change scenarios on Canadian agroclimatic indices

Qian, B., De Jong, R., Gameda, S., Huffman, T., Neilsen, D., Desjardins, R., Wang, H. and McConkey, B. 2013. Impact of climate change scenarios on Canadian agroclimatic indices. Can. J. Soil Sci. 93: 243–259. The Canadian agricultural sector is facing the impacts of climate change. Future scenarios of agroclimatic change provide information for assessing climate change impacts and developing adaptation strategies. The goal of this study was to derive and compare agroclimatic indices based on current and projected future climate scenarios and to discuss the potential implications of climate change impacts on agricultural production and adaptation strategies in Canada. Downscaled daily climate scenarios, including maximum and minimum temperatures and precipitation for a future time period, 2040–2069, were generated using the stochastic weather generator AAFC-WG for Canadian agricultural regions on a 0.5°×0.5° grid. Multiple climate scenarios were developed, based on the results of climate change simulations conducted using two global climate models – CGCM3 and HadGEM1 – forced by IPCC SRES greenhouse gas (GHG) emission scenarios A2, A1B and B1, as well as two regional climate models forced by the A2 emission scenario. The agroclimatic indices that estimate growing season start, end and length, as well as heat accumulations and moisture conditions during the growing season for three types of field crops, cool season, warm season and over-wintering crops, were used to represent agroclimatic conditions. Compared with the baseline period 1961–1990, growing seasons were projected to start earlier, on average 13 d earlier for cool season and over-wintering crops and 11 d earlier for warm season crops. The end of the growing season was projected on average to be 10 and 13 d later for over-wintering and warm season crops, respectively, but 11 d earlier for cool season crops because of the projected high summer temperatures. Two indices quantifying the heat accumulation during the growing season, effective growing degree days (EGDD) and crop heat units (CHU) indicated a notable increase in heat accumulation: on average, EGDD increased by 15, 55 and 34% for cool season, warm season and over-wintering crops, respectively. The magnitudes of the projected changes were highly dependent on the climate models, as well as on the GHG emission scenarios. Some contradictory projections were observed for moisture conditions based on precipitation deficit accumulated over the growing season. This confirmed that the uncertainties in climate projections were large, especially those related to precipitation, and such uncertainties should be taken into account in decision making when adaptation strategies are developed. Nevertheless, the projected changes in indices related to temperature were fairly consistent.

Influence of Seeding Date and Growing Season Conditions on Forage Yield and Quality of Four Annual Crops in Northeastern Saskatchewan

Field experiments were conducted in 2002 and 2003 on a Black Chernozem (Udic Boroll) silty clay soil at Melfort, Saskatchewan, to determine the effects of seeding date on forage dry-matter yield (DMY) and quality [protein and acid detergent fiber (ADF) contents] of four annual crops [barley (Hordium vulgare L.), oat (Avena sativa L.), triticale (× Triticosecale Wittmack L.), and foxtail millet (Setaria italica L. Beauv; hereafter called Golden German millet)] with various maturities as well as different growing-season temperature and moisture requirements. Seeding date had a significant effect on forage DMY of all four crops in each 2002 and 2003. In 2002, the greatest forage DMY for barley, oat, triticale, and Golden German millet was achieved on 3 July, 22 June, 3 July, and 24 May, respectively. In 2003, the greatest forage DMY was from the 24 May seeding date for all four crops. In both 2002 and 2003, protein content in forage tended to decrease as DMY increased in all crops. In 2002, protein content in forage tended to be greater for the cereals with the early seeding dates and lowest days to harvest. The greatest protein content in forage for Golden German millet occurred at the latest seeding date but the fewest days to harvest. In 2003, the greatest protein content in forage occurred at the latest seeding date and fewest days to maturity for all four crops. In both 2002 and 2003, ADF content in forage responded inversely to protein content in forage. The ADF content in forage tended to increase as DMY of all crops increased and days to harvest increased. The seeding date for maximum DMY of cool-season crops was greatly influenced by the growing-season conditions in this study whereas the seeding date of the one warm-season crop was not. In conclusion, the findings suggest that date of seeding of annual forage crops would affect forage yield, and rainfall distribution throughout the growing season also plays a significant role in annual crop forage yields. As long as there is adequate precipitation later in the growing season, late seeding can also result in good forage yields.

Economic Analysis of Three Soil-Surface Practices for Production of Fresh Market Tomato (Solanum lycopersicum L.)

Plastic and cover crop mulches are widely used in a number of vegetable crop production areas, but they currently are not commonly used in California. Evaluations of the effects of silver UV reflective plastic (RP) and cool-season cover crop (CC) mulches relative to the standard, bare-ground production system (ST) on growth, yield, and costs and returns of tomatoes were conducted in California. Biomass increased earlier over the RP mulch and was nearly twice that of both the ST and CC mulch at harvest. Yields were higher for RP (62,022 kg ha−1) and lower in the ST (37,467 kg ha−1) and CC mulch (25,005 kg ha−1) systems in 1999, and also highest in the RP in 2000. Costs in both the RP and CC mulch systems were higher than in ST system in both years and, based on returns on investment, were warranted in the RP system in both years, but only in 1999 in the CC system compared to the ST system. RP mulches may thus be a viable alternative for fresh market tomato production in California. CC mulches may be a useful alternative if productivity can be maintained using sustained no-tillage techniques.

Strip Tillage and Oat Cover Crops Increase Soil Moisture and Influence N Mineralization Patterns in Cabbage

Strip tillage (ST) is a form of conservation tillage in which disturbance is limited to the crop rows while the rest of the soil remains undisturbed. Compared with conventional, full-width tillage (CT), ST may reduce tillage costs, protect soil from erosion, and benefit cool-season crops including cabbage (Brassica oleracea L. var. ‘capitata’) by improving water retention, reducing soil temperatures, and improving the synchrony of inorganic nitrogen (IN) supply with crop demand. Field experiments were conducted in 2010 and 2011 in central Michigan to assess the effects of tillage (CT vs. ST) and a preceding cover crop (none vs. oats, Avena sativa L. var. ‘Ida’) on soil temperature, moisture, N dynamics, and yields in transplanted cabbage. Oats were sown in April and terminated 2 to 3 weeks before cabbage transplanting in early July. In-row (IR) soil moisture, temperature, and IN content were assessed from transplanting until cabbage harvest in October. In 2010, IR soil moisture was higher season-long in ST compared with CT and in oat compared with non-oat treatments, but these effects were not detected in 2011. Tillage and oat residue had little or no effect on IR soil temperature. Shortly after tillage in both years, soil IN availability was greater in CT treatments without oats compared with both ST treatments and CT with oats. However, these differences dissipated after 3 to 4 weeks, and hypothesized improvements in N release patterns under ST were not observed. No differences in cabbage marketable yield were detected in either year, although the proportion of plants that produced a marketable head was lower in cover-cropped plots in 2010. These findings suggest that soil conservation and input savings potentially associated with ST production systems may be attained without a yield penalty. More research is needed to understand and optimize cover crop management in ST systems to realize potential benefits in N use efficiency, moisture retention, and soil temperature moderation.

North Florida Gardening Calendar

Give cold-damaged palms proper care to encourage their recovery in February. In April, monitor landscape plants weekly for aphids on tender new growth. Annuals that can take full sun during hot summer months include celosia, portulaca, vinca, and some coleus. In September, plant cool-season vegetable crops, such as radish, carrot, cabbage, and lettuce. This 10-page fact sheet tells what to plant and what to do in your north Florida garden year-round. Written by Sydney Park Brown, and published by the UF Department of Environmental Horticulture, April 2012. ENH1190/EP451: North Florida Gardening Calendar (ufl.edu)

Genetic Variability on Seed Yield and Related Traits of Elite Faba Bean (Vicia faba L.) Genotypes

Faba bean is one of the most important cool season crops in the highlands of Ethiopia and the country is considered as the secondary center of diversity. This study was conducted at Haramaya, Boreda and Hirna districts of Eastern Hararghe from 2006 to 2008 cropping season using twenty five elite genotypes of faba bean to determine the extent and pattern of genetic diversity for seed yield and related traits. The treatments were arranged in a randomized complete block design with three replications. The data were subjected to the analyses of variance using the SAS program. The mean squares due to genotypes were highly significant for seed yield (p < 0.01) indicating the existence of sufficient genetic variability for seed yield. Mean squares due to the interaction between year and location were highly significant for all the traits studied (p < 0.01). High genotypic coefficient of variation (10093.53%) was observed for seed yield followed by number of seeds per plant (325.45%). The estimated values of phenotypic variances were in the range of 0.60 for number of seeds per pods to 196564.64 for seed yield. Genetic gains that expected from selecting the top 5% of the genotypes, as a percent of the mean, varied from 12.32% for number of seeds per plant to 35.46% for seed yield. The average linkage technique of clustering produced a more understandable portrayal of the 25 faba bean genotypes by grouping them into five clusters. The maximum distance was found between cluster three and five (D2 = 691.47). Thus, the materials tested in the entire experiment will be maintained for further breeding program.

A 2-Year Small Grain Interval Reduces Need for Herbicides in No-Till Soybean

This study measured weed interference in soybean and corn as affected by residue management tactics following a sequence of oat and winter wheat. Residue management tactics compared were conventional tillage, no-till, and no-till plus cover crops. Treatments were split into weed-free and weed-infested conditions; prominent weeds were green and yellow foxtail and common lambsquarters. Grain yield of soybean did not differ between weed-free and weed-infested conditions with no-till, whereas weeds reduced yield 25% in the tilled system. Corn responded inconsistently to treatments, with more than 40% yield loss due to weed interference in 1 yr with all treatments. Cover crops did not improve weed management compared with no-till in either crop. Seedling emergence of the weed community differed between tillage and no-till; density of weed seedlings was fivefold higher with tillage, whereas seedling emergence was delayed in no-till. The initial flush of seedlings occurred 2 to 3 wk later in no-till compared with the tilled system. Designing rotations to include cool-season crops in a no-till system may eliminate the need for herbicides in soybean to manage weeds.