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The dry-weight-rank method of botanical analysis was tested in the highveld of the Eastern Transvaal and was found to be an efficient and accurate means of determining the botanical composition of veld herbage. Accuracy was increased by weighting ranks on the basis of quadrat yield, and by allocation of equal ranks to species with a similar contribution to yield within a quadrat. Although multipliers derived from local data gave the most accurate estimates, the gain in precision was only marginal as compared with estimates obtained with the use of the original multipliers proposed by 't Mannetje & Haydock (1963). The use of the latter is recommended. A regression relating accuracy of estimates of botanical composition to sample size was established. Possible applications of the method in studies on veld are briefly indicated. UITTREKSEL Die droë-massa-rangorde as 'n metode van botaniese ontleding is in die Oos Transvaalse Hoeveld getoets en is bevind n doeltreffend en akkumte metode om botaniese samestelling van veld te bepaal. Akkuraatheid is verhoog deur beswaring van rangorde op basis van kwadraat opbrengste en deur die toekenning van dieselfde rangorde vir spesies metgelyke opbrengste in n kwadraat. Ten spyte daarvan dat koëffisente afgelei vanaf plaaslike data die mees akkumte beraming gegee het, was die verhoging in akkuraatheid gering in vergelyking met beraming vanaf die oorspronklike koëffisient soos voorgestel deur 't Mannetje & Haydock (1963). Die gebruik van laasgenoemde word aanbeveel. 'n Regressie wat verband hou met die akkuraatheid van botaniese samestelling en steekproefgrootte is bereken. Moontlike toepassings van die metode in veldstudies word kortliks aangedui.

Single‐eared (Hy × C103) and two‐eared (R71 × B60) corn (Zea mays L) hybrids were grown with their roots confined in 8− ✕ −24‐inch plastic‐lined, soil‐filled trenches. They were subjected to equally severe moisture stress at tassel emergence, silking‐pollination and blister kernel stages. The two‐eared variety was more tolerant to moisture stress at the pollination and blister kernel stages than the single‐eared variety. There was no significant difference in the total grain yield of the varieties to the moisture stress at tassel emergence. Silking was delayed in both varieties during moisture stress at pollination; however, this delay in silking did not reduce the fertilization of the ears and the grain yields of the two‐eared variety as much as the single‐eared variety. The two‐eared variety extracted significantly more water (1–2%) from the soil when under moisture stress. A method for measuring the relative turgidity (RT) of the leaves of the corn plants was developed, and the RT of each leaf on the corn plant was different. The RT decreases from apex to base, with each succeeding leaf. Moisture‐stressed corn plants had RT values 18 percent lower in the leaves near the ear shoot than in the leaves near the tassel. This difference in RT could account for the lack of silk emergence while the tassels continued to shed pollen.

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