Synopsis Maximum length × maximum width × 0.747 was found to be an accurate and reliable method of estimating leaf area in 6 grain sorghum varieties. Using the component of variance technique, it was shown that most of the variability in area from leaf to leaf on the sorghum plants within a set of data was due to position on the plant.

Synopsis Yields were reduced about one‐third due to lodging 1 to 2 weeks before heading and 1 to 2 weeks after heading. Lodging between those periods caused less reduction averaging about 15% just before heading. Early lodging mainly reduced the number of kernels per head and later lodging reduced the size of the kernel. Protein content of the grain was higher in lodged than standing wheat. The total amount of protein per acre, however, was less in lodged areas.

Synopsis A curvilinear relationship between grain yield and leaf area was found. Generally, changes in each of the 3 yield components were responsible for yield differences, although number of seeds per head and seed weight underwent greatest change. Greater yield reduction resulted from removing leaf area from upper than from lower portions of the plant. Likewise, removing alternate leaves was more deleterious than removing half of each leaf. In 1959, mean yield decreases of 23, 35, 43, and 95%, respectively, were obtained from removing approximately 33, 50, 67, and 100% of the leaf area at late boot and anthesis stages.

ORGHUMS are a typical warm-season crop. Planting them in soil at low temperatures is deleterious to rapid establishment and vigorous seedling growth. Perhaps considerable variation in low temperature tolerance exists among currently available genotypes, but little information is available on this. Most sorghums originated in tropical areas near the equator (5), but Vavilov (5) places the origin of kaoliang in the Chinese center of crop origin. This center includes the mountainous regions of central and western China and their adjacent lowlands. Most kaoliangs are 'tall and have dry, woody, slender stalks. In general, they are sparsely leaved (3). Because of their northerly origin, it is reasonable that the kaoliangs might germinate and grow at lower temperatures than present-day grain sorghums grown in the United States (2). No critical data are available this question, however, and only limited information is available on temperature-germination responses in sorghums. Martin et al. (4) germinated four types of sor

T\ROUGHT is a problem almost every year in many *-* areas of the world. Drought reduces both quality and quantity of plant material produced and is a major factor in preventing stabilization of agriculture. • Nitrate is the principal form of nitrogen absorbed by higher plants. However, before it can be used in amino acid and protein synthesis, it must be reduced to ammonia. The first step in this reduction process is conversion of nitrate to nitrite by the nitrate reductase enzyme. With available nitrate nitrogen, reduced activity of the enzyme may result in nitrate accumulation. Reduced nitrate reductase activity has been attributed to decreased light, low moisture, low fertility, genotype differences, and possible other factors. In some cases, nitrate has accumulated in sufficient quantities to be toxic to livestock. As early as 1895, Mayo (7) reported losses of cattle that had eaten corn fodder containing 25% potassium nitrate. Molybdenum has been reported to be a metal constituent of the nitrate reductase enzyme. Thus, moisture stress may influence nitrate reduction by limiting molybdenum uptake or availability. Decreased nitrate reduction in plants under stress may influence the quantity and/or quality of other nitrogen fractions and of total nitrogen. West (8) found that water stress quantitatively reduced protein in corn seedlings germinated from 1 to 6 days in darkness, apparently by slowing protein degradation in the endosperm-scutellum and protein formation in the seedling. Chen et al. (2) reported protein levels in citrus seedlings responded differentially to intensifying water deficits. A 3-phase system of protein fluctuation was detected; protein increased at the beginning of dehydration, decreased at medium dehydration, and increased again slightly at extreme dehydration.