Effect of Sequential Planting, Plant Replacement, and Planting Date on Marketable Yield of Bell Pepper, Capsicum annuum var. annuum L.
Earliest plantings of the bell pepper cv. Pip were on 16 May 1990 and 15 April 1991 at Lane, Okla. Additional plantings were at monthly intervals through July. Peppers were harvested weekly. Plants of the earliest plantings had marketable yields of approximately 21 Mg. ha-'. Marketable yields of later plantings were no higher than 8.6 Mg, ha-'. Combined marketable yields of sequential monthly lantings increased marketable yield to approximately 36 Mg.ha-(I a 1.7 fold increase over the earliest planting alone. W~th the earliest planting removed and peppers immediately replanted in June or July 1990 or May through July 1991, the marketable yield from subsequent plantings did not equal the marketable yield lost with the earliest planting maintained. Results showed sequential planting, with the earliest planting being no later than early May in the South Central United States, to be a viable method to increase marketable yield of bell pepper.
Sequential Planting for Single-Harvest Vegetables
ABSTRACT At Lane, Oklahoma, bell pepper (Capsicum annuum var. annuum L., cv. ‘Pip’) was followed in sequence with cucumber (Cucumis sativus L., cv. ‘Calypso’), or processing tomato (Lycopersicon esculentum L., cv. ‘Early Pear’), or bunch onion (Allium cepa [L.] Cepa group, cv. ‘Crystal Wax White’). Each crop was harvested once. Each sequence was begun monthly from mid-April to mid-July in each of two years, and with three fertilizer rates (recommended rate [1-fold], and 1.5- and 2-fold the recommended rate). For the earliest planting in both years, the time to first frost was long enough for a third crop. The fourth planting failed in both years. Tomato yields were below normal. The bell pepper and cucumber sequence had the highest yields for the first two planting dates. Increasing fertilizer rate reduced bell pepper yield, but had little effect on yield of crops planted in sequence with bell pepper. Further research is needed to determine how sequencing other crops will affect yield.
On the fractionation of β-lactoglobulin and α-lactalbumin
Abstract Existing methods for the preparation of α-lactalbumin and β-lactoglobulin are examined critically. It is proposed that the most satisfactory method for the preparation of the whey protein fraction from bovine milk is (NH 4 ) 2 SO 4 fractionation. A number of new gentle procedures for the fractionation of the whey proteins are compared with some existing methods. The distribution of total protein at various stages is determined by total Kjeldahl nitrogen and the kind of protein by starch-gel electrophoresis. The effect of variables, such as pH, salt concentration and temperature on the separation of α-lactalbumin and serum albumin from β-lactoglobulin is studied. Differences in the behavior ( e.g. solubility) of genetic variants of β-lactoglobulin are noted. The solubility of each of the major whey proteins, under similar conditions to those used in the fractionation, is compared with its solubility in the whey protein mixture. The understanding gained of factors important in the fractionation is used in recommending new procedures for α-lactalbumin and β-lactoglobulin isolation.