A field trial of cowpeas (Vigna unguiculata (L.) WALP.) was performed in the dry season at Kano in Sudan Savanna of Nigeria. Grain yield of highly drought-tolerant lines (Tvu 11979, 11986, 12348) was around 1 t/ha. While that of highly susceptible ones (Tvu 7778, 8256, 9357) was only about 0.2-0.3 t/ha. The productivity of 1 t/ha was similar to that recorded in the rainy season at Kano. This trial confirmed previous evaluation of drought tolerance of cowpea lines. It also suggested that highly tolerant lines could be cultivated in the dry season in farmers' fields.
Two cowpea lines (Tvu 11979: highly tolerant to drought, Tvu 9357: highly susceptible to drought) were cultivated in pots at Tsukuba, Japan. Half of the pots were subjected to water stress (hereafter referred to as stressed plot) and the others were watered periodically (control plot) . In the stressed plot, dry matter increase per plant was markedly and equally reduced in both lines and no defferences was observed between the highly tolerant line and the highly susceptible one. The distribution of dry matter among plant organs, however, was different at the ripening stage between the two lines. In the highly tolerant line, a larger proportion was distributed to roots, and a smaller proportion to pods in comparison with the highly susceptible one. This characteristics of highly tolerant lines seemed to be very advantageous for collecting residual water from deep soil and for dry matter production in the dry season. However, when the lines were planted in pots, the root zone was limited. The vigorous growth of roots of these tolerant lines, therefore, could be ineffective in collecting water in potted plants.

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In Sudan Savanna, late arrival of the rainy season delays both planting and maturity of crops. Delayed maturity far into the dry season leads to exposure to drought at the ripening stage and yield loss. Root elongation, however, under water stress enables roots to capture receding residual soil moisture. Elongation rate of the longest root under water stress, therefore, was compared among seedlings of cowpea lines (Vigna unguiculata (L.) WALP.), differing in drought tolerance. Thin acrylic pipes were used for pots to trace the daily root elongation.
In the first experiment, root elongation rate of highly tolerant lines was less reduced under water stress than that of highly susceptible ones. Distribution ratio of dry weight of roots among soil layers was also less affected by the stress, the ratio in deeper soil layers being as large as that in the control plot. In contrast, the ratio in deeper soil layers decreased under water stress in highly susceptible lines.
In the second experiment, root elongation rate was measured in five kinds of soil, whose moisture content was kept at 13, 11, 9, 7 and 5 percent (w/w) respectively throughout the experiment. Decrease of the rate was observed at a moisture content of 9% in a highly susceptible line, whereas at 7% in a highly tolerant line. Depression of root growth at a lower moisture content observed in a highly tolerant line seemed to be one of the characteristics responsible for drought tolerance in cowpeas.

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Variation of caryopsis size and shape in 272 strains of foxtail millet, Setaria italica (L.) P. BEAUV. was studied to clarify the genetic diversity and characterize landraces collected from different regions. A significant difference was detected in the caryopsis size between the strains originally collected from an area extending from the Far East to Southeast Asia and those from other regions. The strains from Japan, Taiwan, Southeast Asia and limited parts of South Asia (Nepal and Bhutan, Orissa, Madhya Pradesh and Maharastra in India) had small caryopses, whereas those from China, most parts of South Asia and its northwestern vicinity, Central Asia and Europe had large caryopses. The strains with round caryopses were mainly found in East Asia, Taiwan Island, some parts of South Asia and western Europe. The center of diversity in caryopsis size and shape was located in South Asia, particularly India and its northwestern vicinity.

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Effects of application of oil palm bunch ash (OPBA) on the growth of maize (Zea maysL., cv. Masmadu) and soil properties were examined in a field experiment in a woody peat soil in Malaysia. Without soil pH amendment, due to the high acidity of the soil, the growth of maize was very poor and the plants died before tasseling time, even though NPK fertilizers and micronutrients were applied. The application of OPBA which is rich in potassium and is an alkaline material was effective in amending the soil acidity, but caused problems in the emergence of seedlings and growth performance of maize; i.e., injury in emergence probably caused by alkaline pH and high concentration of potassium and an abnormal morphological symptom referred to as “leaf serration”were frequently observed at higher level of OPBA application. Leaf serration was considered to result from calcium deficiency due to the suppression of calcium uptake associated with a high concentration of potassium from OPBA. The grain yield in the OPBA plot was much lower than that in the ground magnesium limestone (GML) application plot. Optimum growth and grain yield were obtained with GML treatment. Mixed application of OPBA and GML resulted also in adequate plant shoot growth and grain yield. OPBA was highly soluble in water giving an alkaline solution, and solubilization of peat soil organic matter which was observed in the field, was confirmed by a laboratory experiment. In comparison with GML addition, the decomposition of peat soil organic matter was not stimulated to any great extent by OPBA addition. It was concluded that OPBA would not be useful as soil acidity amendment alone, but could be used as an alternative soil pH ameliorant and/or fertilizer in a limited amount in conjunction with other liming materials.

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Studies on pollen ecology and genetical analyses of flowering characteristics for F₁seed production in barley were carried out.
The amount of pollen shed in the daytime was larger than that during the night. The velocity of the wind in the daytime was also higher than during the night. Most of the pollen grains in the daytime flew out and those at night successfully reached the female parent.
In the field of the breeding station, the method to obtain F₁seeds with a high purity and limited labor was as follows: the populations of F₁seeds were alternately planted in row with male sterile plants and in rows with pollen parents; the populations of F₁seeds were enclosed by three rows of rye.
Most of the Japanese cultivars showed cleistogamy and most of the foreign cultivars revealed chasmogamy. The analyses of flowering characteristics in the B₁F₂generation of the cross, Misato Golden×2/Satsuki Nijo, clearly indicated that the chasmogamy was controlled by a single recessive gene.
As the chasmogamous character is controlled by a single recessive gene, the pollen parents for F₁seed production can be easily developed by conventional methods of breeding.

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Three hundreds barley germplasm accessions collected in Tunisia were evaluated for agronomic characters. Tunisian barley accessions showed a considerably wide variation for heading date, maturing date, culm length and spike length. Compared with Japanese cultivars used as control, Tunisian lines showed late heading and a long culm. On the other hand, 1000 kernel weight of the Tunisian lines was larger than that of the Japanese cultivars. Lines collected in the northern part of Tunisia showed a longer culm and shorter spikes, while those in the southern part showed a shorter culm and longer spikes. Although most of lines collected in Tunisia were susceptible to barley yellow mosaic virus, two lines were resistant. Seventy five lines among the 149 lines tested were resistant to powdery mildew. Most (66%) of lines tested showed spring habit, fourteen lines showed winter habit and the others showed on intermediate habit. These Tunisian barley accessions can be used for barley breeding.

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In order to detect lines with reciprocal translocations in barley plants collected in Tunisia, ten lines with a short culm were crossed with Tunisian lines with the standard karyotype, ESAK 33 and Peru lima 2959.
The F₁plants from the two crosses showed a semi-sterility, while their parents were normally fertile. The chromosome configurations in PMCs at metaphase I (M I) consisted of one quadrivalent and five bivalents, indicating that these lines (BGR52 and BGR53) had a single reciprocal translocation. Furthermore, in order to identify translocated chromosomes in these translocation lines, the translocation tester lines derived from Mars were crossed with two Tunisian translocation lines. The hybrids between these Tunisian lines and translocation tester lines, T1-7a, T1-7b, T1-7c and T4-5b formed 1 VI+4 II pairs at M I. Hybrid between BGR52 and BGR53 formed 7II pairs. Therefore, two of the ten barley germplasm accessions collected in Tunisia carried the spontaneous reciprocal translocations. Translocated chromosomes consisted of chromosome 5 and chromosome 7. Two spontaneous reciprocal translocation lines carried the same translocated chromosome.

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In order to develop suitable criteria to irrigate an onion (Allium cepaL.) cultivar, Taherpuri in an agroecological zone of Bangladesh (Madhupur Tract, AEZ no. 28), a field experiment on its yield response and water use in relation to different irrigation schedules was carried out. A significant improvement in the yield attributes and bulb yield was observed by supplemental irrigation. The plots irrigated at 10 and 20% depletion of field capacity moisture (DFCM) produced bulb yields of 16.29 and 16.27 ton/ha, respectively, which were about 140% higher than that in the unirrigated control plots (6.80 ton/ha) . Bulb yields of the plots irrigated either at 30 and 40% DFCM (13.96 and 11.29 ton/ha) or at 30 mm irrigation water (IW) : cumulative pan evaporation (CPE) ratios of 0.50, 0.75, and 1.00 (8.75, 9.81, and 11.32 ton/ha) were significantly higher than that of the control but still remained at a suboptimum level. The estimated total water use of the aforesaid two highest-yielding treatments was 263 and 274 mm, respectively. The water use efficiency in terms of irrigation water was maximum in these two plots. It was concluded that for optimum exploitation of the yield potential of‘Taherpuri’onion with maximum efficiency of irrigation water, 10 to 20% DFCM might be the most suitable criteria for irrigation in the experimental site and in the areas with similar conditions.

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For improving the unstable and low production of rain-fed rice in Northeast Thailand, the possibility of application of two kinds of methods was studied using a growth simulation model. In the first method, a watershed area in a patch of the paddy field increased slightly the rice yield per planted area but decreased the total production from the patch of the field. Therefore this method was found to be ineffective for improving rain-fed rice production. In the second method, introduction of direct seeding culture, extended the range of seeding times and enabled to achieve a yield which could not be realized by the transplanting method because of the water shortage for transplanting of seedlings.

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