Search Results
Abstract
‘Giant Cavendish’ (‘Williams Hybrid’) banana (Musa acuminata Colla) was grown at the Waimanalo Research Station on Oahu, Honolulu, in 8 blocks with 48 mats per block. Nitrogen was applied as a continuous gradient across the width (6 mats) of each block. Potassium applications varied continuously over the length (8 mats) of the block. A 10 cm wide strip of leaf lamina was secured on a monthly schedule from each side of the midrib at the widest point of the 3rd fully unfurled leaf of (nonbearing) shoots which received the 4th level of N and the 5th level of K. Mats from which these samples were taken were designated as control mats, with the amount and frequency of fertilization applied sufficient to maintain them at about 2.6% N and 3.2% K. Other mats were fertilized on the same schedule as the control mats. Amounts of fertilizer applied were always in a fixed ratio, both greater than and less than the control mats. A leaf sample was secured from each shoot of each mat soon after the flower bud had emerged. The 3rd full-sized leaf below the inflorescence was sampled. Leaf N levels were associated with banana yield. Yields approached maximum at about 2.8% N. Amounts of N fertilizer required were increased greatly by a heavy infestation of Cyperus rotundus L. This weed decreased yields independently of its competitive effects for N. There were few indications of a K deficiency under the conditions of this trial, although heavy K fertilization was required to maintain leaf K at 3.2% in the control mats. The results of K fertilization suggest that surface application is not a very effective means of supplying K to banana plants. The general pattern of K uptake indicated that banana was utilizing K from the subsoil. Suspected incipient sulfur deficiency was not confirmed.
Abstract
The microclimate surrounding ‘Rome Beauty’ apples (Malus × domestica Borkh.) was modified by enclosing clusters at petal fall (PF) in various types of bags, and the influence of these treatments on development of scarf skin, cuticular waxes, and peel nutrient status was determined. The cuticle and epidermis of fruit with scarf skin generally was unbroken, but cell separations several cell layers below the surface resulted in gaps or air spaces which caused the visual whitish-gray appearance (scarf skin). Energy dispersive x-ray analysis and tissue analysis of apple peel indicated an increase in concentration of Al, Ca, and Mn with severe scarf skin. All bag types reduced scarf skin compared with the unbagged control, with cheesecloth giving the smallest reduction (34% on green side) and the large polyethylene bag the largest reduction (75% reduction green side). The total amount or components of cuticular wax was not influenced by the bagging treatments or by the different levels of scarf skin. Light level, temperature, and absolute and relative humidity were modified by the various types of bags, but the role of the individual environmental parameters on the expression of scarf skin was not indicated.