The annual cycle of reproduction in many birds is regulated by seasonal changes in day length. While a great deal is known about the temperate forms, photoperiodic control of reproduction in tropical and subtropical birds are scanty. Due to the lack of experimental data concerning photoperiodic regulation of reproduction in subtropical and tropical birds, particularly females, we performed the above experiment using subtropical female house sparrow, a resident passerine bird. House sparrow is unique among photoperiodic species in that daily photoperiods of both greater and lesser duration than minimum induces gonadal growth. In the view of contradictory opinion expressed from a number of authors regarding photoperiodic responses of house sparrow, we conducted experiments with photosensitive subtropical female house sparrow in which the birds were exposed to continuous light (LL), continuous dark (DD), short days (8L: 16D), long days (15L: 9D) and natural day length (NDL) . Data from the birds exposed to continuous light and long days shows that ovarian growth was followed by regression and onset of refractoriness; short days and continuous dark failed to make any ovarian response and natural day length capture bird, show gonadal growths only when they received increasing day length of summer. The sparrows exposed under different treatment did not show any significant variation in their body weight responses.
Our results conclude that:
(a) The subtropical house sparrow is photosensitive and light stimulation is a prerequisite to its reproductive activities.
(b) The photoperiodic responses of this bird seems to support the Bunning Hypothesis (external coincidence model) .

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To maintain the bulbs or rootstocks at low temperature, those of Lilium×elegans Thunb. cv.‘Benisugata’and‘Connecticut King’, Lilium×formolongi hort, cv.‘Hakuho’and the blazing-star Liatris sp. cv.‘Kouki’were stored in snow occupying a chamber made of 10 cm thick polystyrene panels, from 10 January to 10 May 1988. Some of the snow still remained at the end of storage. Bulb temperature varied from 0 to -0.2°C during storage, but rose to 0.6°C toward the end of the period. The leaf number of the plants increased, but no flower-buds appeared during storage.
Lilies and the blazing-star planted on 25 November, 1987 as a control sprouted in late March to middle April and flowered in middle June to early July. However, those planted on 10 May 1988 following storage sprouted in middle May and flowered in early July to early August. The storage caused a decrease in the stem length and node number of‘Hakuho, ’‘Kouki’and‘Connecticut King.’This may have been due to the early initiation of flower-buds at high temperature following planting.

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When the night soil is used as the manure for planktons in seawater, decomposition ratio of night soil has greatly effect upon multiplication ratio of planktons. Two of seawater for culture medium, one high nutritive value, the other low nutritive value, were adopted in this study. Several night soils with different composition ratio were added into the seawater, and numbers of planktons (diatom, other unicellular algaes, dinocontae, and other zooplankton) were measured.
The night soil with the high decomposition ratio was effective on the multiplication of various planktons, especially for diatom or dinocontae. Most of diatoms appeared in the first half of the cultivation period, and most of dinocontaes appeared in the latter half of that period. When the night soil with high decomposition ratio was added into the seawater, phytoplankton early appeared in comparison with the addition of the night soil of low decomposition ratio. Accordingly, it can be said phytoplankton take the decomposed products of night soil as a bait. The multiplication ratio of plankton was changed by difference of the seawater. The fact suggested that effect of decomposition ratio on multiplication ratio depended on the concentration of nutritive value in seawater.

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The reversible photoreaction of R (Red light) and FR (Far-red light) controlling the seed germination in Grand Rapids lettuce (Lactuca sativa L.) varies markedly not only with germination temperature, but also with the physiological state of seed caused by ageing. The photoreversibility in Grand Rapids lettuce seeds is more evident in the dormant (fresh) and deteriorating (60 and 66 months after harvest) seeds. The reversibility in the non-dormant seeds, however, can be induced again by a prolonged expooure to FR light or high (40°C) temperature pretreatment after the onset of imbibition. The velocity and the viability in germination of the seeds exposed to the prolonged FR light or heat-sensitized at 40°C for 48 hr maintained for a longer time than in the seeds having no exposure to FR light or heat-sensitization. The photoreversible induction by the prolonged exposure to FR light is due to the secondary photo-dormant stage of the seeds. The photo-reversible induction by a heat-sensitization after the onset of imbibition, on the other hand, is due to the two different physiological states of the seed; a, the secondary thermo-dormant stage caused at 40°C for 48 hr, and b, the deteriorating stage caused by the thermal injury at 40°C for 144 hr. Germination induction effects in the heat-sensitized seeds with high temperature pretreatment after the onset of imbibition are greater in GA₃ than in R light.

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To establish the optimal environmental control in hydroponics, we measured the diurnal courses of net CO₂ uptake and NO₃- consumption of tomato plant cultivated in nutrient film culture and then tried to make the dynamic models of these physiological processes as affected by light intensity based on system identification. Furthermore, online identification was applied to these processes.
Two types of dynamic models which are the linear model obtained by the method of least squares and the nonlinear model obtained by the GMDH (Group Method of Data Handling) were used in the identification.
Using the nonlinear model, we could identify the processes of net CO₂ uptake and NO₃- consumption as affected by light intensity with satisfactory results. On the other hand, using the linear model in the process of NO₃- consumption to light intensity increased the mean square error between the calculated and the observed responses. In the process of net CO₂ uptake to light intensity, however, we could identify using the linear model with satisfactory results. This implies that online identification based on a linear model is effective to the process of net CO₂ uptake as affected by the light intensity from the view of efficient identification.

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We are going to develop a stand-alone computer integrated cultivation support system.
It has three special functions in contrast to usual environmental control system. Those functions are environmental control planning, interactive man-machine interface and diagnosis of environmental control machines.
This system is composed of powerful microcomputer unit, measurement unit, control unit, signal conditioning units for various sensors, system program and five application programs.

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