Judul: Fenologi Pembungaan dan Penyerbukan Buah Naga Hylocereus undatus, Hylocereus costaricensis dan Selenicereus megalanthus
Abstrak: The objectives of this reseach was to observe flowering phenology of dragon fruit (Hylocereus undatus, Hylocereus costaricensis and Selenicereus megalanthus) and to investigate if pollination types affect fruit quality. This research consisted of two experiments; the first is observation on flowering phenology. The second experiment was arranged in randomized complete block design with type of pollination as the treatment, i.e open pollination of H. undatus (P1), controlled self pollination of H. undatus (P2), controlled cross pollination of H. undatus x H. costaricensis (P3), open pollination of H. costaricensis (P4), controlled self pollination of H. costaricensis (P5), and controlled cross pollination of H. costaricensis x H. undatus (P6). The treatments were repeated 4 times. Development of flower bud until blooming in Hylocereus spp. was about 19-21 days, while in S. megalanthus took 29-31 days. Based on pollen viability and stigma receptive period, the optimal pollination time was between 11.00 pm to 2.00 am for the three species. All types of pollination resulted in 100% fruit set. Fruit weight from self pollination of H. costaricensis was the highest among types of pollination, while total soluble solid from controlled cross pollination of H. undatus x H. costaricensis was the highest. Controlled pollination, both self and cross of H. costaricensis produced bigger fruit than open pollination.
Keyword: receptivity stigma, pollen viability, fruit set, self pollination

Judul: Induksi Pembungaan dengan Penambahan Penyinaran dan Pengaruh Dmur Bunga terhadap Pembentukan Buah pada Hylocereus spp.
Abstrak: The aim of this research was to study the effect of extended light on flowering off season and to investigate if over anthesis flowers were potential for fruit production of Hylocereus spp. The study consisted of two experiments both were arranged in randomized complete block design (RCBD) with one factor. Lamp power (45 watts, 55 watts and without extended light) was the factor for the first experiment with 3 replications. In the second experiment flowers age was used as treatment, i.e. pollination at anthesis (0 hours after anthesis /HAA), 6, 12 and 18 HAA, and each was applied on 7 flowers. The results from the first experiment showed that extended light with 45 and 55 watts for 11 hours/day induced off season flowering in dragon fruit after 54 days. The development of induced flowers was similar to those on season flowers (19-21 days), yet fruit set of the off season flowers were only 39.5% (45 watts) and 66.6% (55 watts). From the second experiment it was found that pollination was successfully carried out at anthesis until 12 HAA with 100% fruit set and marketable fruit size. Pollination at 18 HAA though produced marketable fruit size; however the fruit set was only 14.3%.
Keyword: lamp, dragon fruit, day length, cross pollination

Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix