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Growth responses of Kentucky bluegrass (Poa pratensis) `Touch Down' to elevated levels of micronutrients were investigated. Plants established in peat-lite mix in 10-cm pots were constantly fed with fertilizer solutions containing 0.5, 1, 2, 4, 6, 8, or 12 mM of boron (B), chloride (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), or zinc (Zn) for 7 weeks. The control solution had (in μM): 20 B, 0.5 Cu, 40 Fe, 10 Mn, 0.5 Mo, and 4 Zn. All treatment solutions had a standard macronutrient concentration. Foliar toxicity symptoms developed first in B treatments followed by Mo treatments. The lowest microelement concentrations that showed visual toxicity symptoms were: 0.5 mM B, 12 mM Cl, 1 mM Cu, 2 mM Fe, 0.5 mM Mo, and 1 mM Zn. A reduction in dry matter yield was evident when the nutrient solution contained 2 mM B, 4 mM Cu, 12 mM Fe, 2 mM Mo, or 4 mM Zn. Chloride and Mn did not alter biomass yield in the concentration range tested. Both the chlorophyll-a and -b contents decreased as B levels in the fertilizer solution increased. Chlorophyll contents increased with elevated levels of Fe in the fertilizer solution.
Abstract
Ammonium sulfamate (Animate X) gave the best results for controlling resprouting of tree stumps of avocado (Persea americana Mill.).
Abstract
Lemons (Citrus limon (L.) Burm. f.) were stored for up to 27 weeks at 10°C in air and in an atmosphere of 3 to 5% O2 and 0.1 to 0.2% CO2, with and without an ethylene absorbent. Mold incidence was high in controlled atmosphere (CA) storage where ethylene accumulated, but removal of ethylene reduced its development. CA storage improved retention of green color in lemons.
The effect of increasing micronutrient levels on buffalograss (Buchloe dactyloides) was investigated. Seedling plants established in peat-lite mix in 10-cm pots were irrigated with solutions containing 0.5, 1, 2, 4, 6, 8, or 12 mM of boron (B), chloride (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), or zinc (Zn). The control solution contained (in μM): 20 B, 0.5 Cu, 40 Fe, 10 Mn, 0.5 Mo and 4 Zn. A standard macronutrient concentration was used for all treatment solutions. Boron and Mo induced visual toxicity symptoms more readily than other micronutrients. Boron toxicity was characterized by chlorosis often accompanied by bleached leaf tips, while Mo toxicity resulted in leaf necrosis. The lowest levels that induced foliar toxicity symptoms were: 0.5 mM B, 2 mM Cu, 4 mM Fe, 6 mM Mn, 1 mM Mo, and 4 mM Zn. Chloride did not induce foliar abnormalities in the concentration range tested. Biomass yield was reduced when the nutrient solution contained 2 mM B, 8 mM Cu, 2 mM Mo, or 12 mM Zn. Elevated levels of Cl, Fe and Mn did not alter dry matter yield. Tissue concentrations of micronutrients were also determined.
The growing conditions of North Dakota are characterized by short frost-free seasons (< 120 days), long photoperiods, a large fluctuation in summer temperatures, and fertile soils especially in the Red River Valley region. Commercial production of vegetables in the state has been increasing with renewed interests in fresh and processed products. Currently, about 1,200 acres are devoted to vegetable production in the state with most of it conentrated in the eastern part of the state. This excludes 158,000 acres used for potato production. The top ten vegetables, excluding potato, are onion, carrot, sweet corn, squash, cabbage, red beet, muskmelon, asparagus, pumpkin, and garlic in the descending order of acreages devoted. While onions are grown mainly for fresh markets, carrots are produced for both fresh and dehydrated products. Acreages for these two crops are expected to expand, especially for supplying onions for ringing operations and carrots for dehydration and p-carotene extraction. Each year, selected cultivars of onions, carrots and other vegetables are evaluated for their performance in this northern growing environment.
Mississippi's two largest tomato-growing areas are in Smith and George Counties. The Truck Crops Branch Experiment Station in Crystal Springs is the closest vegetable research site to Smith County but does not share the same soil type. Tomato spotted wilt virus (TSWV) reduces fruit yield and marketability, and its incidence appears to be increasing in the state. The objectives of this trial were 1) to determine fruit yield and TSWV incidence in tomatoes (Lycopersicon esculentum) grown in central Mississippi, and 2) compare yield and relative yield among cultivars and between locations. Tomato seedlings were transplanted to the field in April 2004 in Smith and Copiah County plots. Production practices included raised beds, black plastic mulch, drip irrigation, and fertilizer applied pre-plant and as side-dressings based on soil test and regionally recommended practices. TSWV incidence was recorded in each plot in Smith Co. in June 2004. In both locations, `Amelia' and `Mountain Spring' were among the top yielding entries. In Smith, the top entries also included `BHN 543' and two commercial experimental entries. In Copiah, `Florida 47 R', `Biltmore', `Mountain Fresh', and `BHN 543' also produced high marketable yields. `Florida 47R', `Bush Celebrity', and `Mountain Fresh' were among the poorest yielding varieties in Smith County. Incidence of TSWV was not formally rated in Copiah. In Smith, percent symptomatic plants per plot were negatively correlated with yield. Symptoms were found on entries reportedly resistant or tolerant to TSWV.