Completing the jigsaw: the first record of the female plant of Daphnopsis filipedunculata (Thymelaeaceae), an endemic species from the Brazilian Amazon

The results of intensive fieldwork in the National Forest of Carajás (FLONA Carajás) led to the discovery of pistillate plants of Daphnopsisfilipedunculata, an endemic species from the Serra dos Carajás, previously known only from staminate individuals. These newly discovered populations add valuable missing information related to pistillate buds, mature flowers and fruits.

Behind the Green Door

Chapter 14 explores literary and scientific reactions to the idea of sex in plants. England experienced a fashion for “phytoerotica”: bawdy verse, in which plants represented human genitalia, and classically inspired poetry, in which stamens and pistils were personified as husbands, wives and lovers. The former had little to do with plants. The latter served to teach the Linnaean sexual classification system. In reaction, some botanists rejected both the sexual theory and the Linnaean system. Two camps developed, the “sexualists” and the “asexualists”. J.G. Siegesbeck railed, “[Who] will ever believe that God Almighty should have introduced such…shameful whoredom for the propagation of the reign of plants.” The negative impact of the sexual system on the morals of women became the asexualist’s rallying cry. In 1759, the Pope banned all Linnaeus’s books and ordered them burned. Nevertheless, Erasmus Darwin’s “Loves of Plants,” with its fascinating female plant characters, was a hit.

Effect of Male Planting Date and Female Plant Population on Hybrid Maize Yield and Evaluation of Use of Hybrid-Maize Simulation Model for Grain Yield Estimation in Hybrid Maize Seed Production

The study was carried out to determine the effect of male planting date (MPD) and female plant population (FPP) on the grain yield (GY) performance of a three-way hybrid and to evaluate Hybrid-Maize simulation model for grain yield estimation in hybrid seed maize production. Fifteen treatment combinations of five MPD as a deviation from the female planting date and three FPP replicated three times were used. The Hybrid-Maize simulation model programme was used to forecast the possible GY outcomes for the fifteen treatments of the experiment using estimated parameters and weather data for the 2006/7 season. The field experiment produced significant (P < 0.005) main effects but non-significant interaction effects for GY, yield components and antheis-silking interval (ASI). Female seed yield was affected by time of male pollen shed relative to female silking: ASI, with highest yields associated with close synchrony (ASI= +/-3 days). ASI had a significant effect on the number of kernels per ear (KPE), with the greatest KPE (318) associated with an ASI of +/-3 days. FPP effects on yield are typical for maize, showing a curvilinear response from low to high density. The optimum population density for GY was 5.4 plants m-2. Simulation output from the Hybrid-Maize simulation model showed an overestimation of GY compare to the observed yield. Furthermore, the model was unable to predict yields for the low FPP of 2.7 plants m-2. We found that Hybrid-Maize simulation model has limited potential for simulating hybrid maize seed production, as it does not accommodate limitations that may occur during the growing season: difference in male and female planting dates, pollen density and dispersion. Hence, the fixed parameters for the Hybrid-Maize simulation model can only be used in maize commercial production.

Karakterisasi dan Evaluasi 10 Aksesi Salak di Sijunjung Sumatera Barat

<p>The study was conducted at the farmer&amp;rsquo;s field in Ujung Batu Sijunjung, West Sumatera using local Salacca cultivars developed from crossing between cultivar Pondoh as female plant and indigenous salak of Sumatera as male plant. This study was held from January 2003 until December 2005. The objective of this study was to develop database of Salacca characters by exploration method and using data passport model. The research result showed that five accessions with yellowish white fruits and the other five accessions with white fruits. The plant that produced fruit with good quality was SNJ-01 and thick flesh (0.57 cm), sweet (18,00oBrix in TSS), crispy, yellowish white in color and contains water 77.02%.</p><p> </p><p><strong>Abstrak</strong></p><p>Penelitian ini dilakukan di kebun petani Desa Ujung Batu Kabupaten Sijunjung Sumatera Barat dengan menggunakan materi tanaman salak yang ada di daerah tersebut yang berasal dari persilangan antara induk betina salak Pondoh dan jantan indigenous Sumatera. Penelitian dilakukan pada bulan Januari 2003 sampai dengan Desember 2005 dan bertujuan untuk menyusun database karakter tanaman salak, metode yang digunakan adalah eksplorasi dan pengumpulan database menggunakan model paspor data. Hasil penelitian diperoleh deskripsi 5 aksesi yang warna buahnya putih kekuningan dan 5 aksesi yang warna buahnya putih. Tanaman yang menghasilkan buah dengan mutu baik, yaitu aksesi nomor SNJ-01, di mana daging buahnya tebal (0,57 cm), manis (PTT = 18,00oBrix), masir, berwarna putih kekuningan, dan kadar air (7,02%).</p>

The role of the male flower spike as a cue for selective grazing in bladder saltbush

This paper reports the results of three cafeteria trials used to study palatability variation between the sex phenotypes of bladder saltbush (Atriplex vesicaria Heward ex Benth.). The results of the first trial show that Merino sheep preferentially grazed female samples compared to male ones, which supported earlier paddock-scale grazing trials and observations. In the second trial, the removal of male flower spikes led to increased consumption of male samples, suggesting that male flower spikes contain a grazing deterrent. The third trial showed that sheep were able to detect male material with or without spikes even when it was completely hidden within female plant material. In combination with observations made during the trials, these results suggest that there is a grazing deterrent present in male plants and that sheep use the male flower spike primarily as a visual cue when making grazing decisions.